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Foam has been employed as an improved or enhanced oil recovery method to overcome gravity override and the channeling and fingering of the injected gas, which arises because of the low density and viscosity of the injected fluid combined with the rock heterogeneity. A major challenge, however, is the stability of the generated foam when it contacts the oil. In this study we investigate the feasibility of using inexpensive nanoparticles made of coal fly ash, an abundantly available waste product of coal power plants, as a foam booster. We investigate the viability of reducing the size of fly ash particles to 100−200 nm using high-frequency ultrasonic grinding. We also study the foaminess (foamability), strength, and stability of the foams made with minor concentrations of fly ash nanoparticles and surfactant, both in bulk and porous media. The effect of monovalent and divalent ion concentration on the foaminess of the nanoash suspension combined with very low concentrations of a commercial alpha olefin sulfonate (AOS) surfactant, in the presence and absence of oil, is studied. We observe that bulk foam that contains very small amounts of nanoash particles shows a higher stability in the presence of model oils. Furthermore, experiments in porous media exhibit remarkably stronger foam with mixtures of nanoash and surfactant, such that the amount of produced liquids from the cores significantly increases. For the first time we show that nanoash can be used to stabilize nitrogen foam in the presence of crude oil at high temperature and pressure. In the presence of oil, the nanoash−AOS foam shows a higher stability, although crude oil tends to form stable emulsions in water in the presence of nanoash.
Derzeit finden gravierende Veränderungen im Umfeld der Informations- und Kommunikationstechnik statt, die eine große Chance für die optimierte Prozessführung und Wertschöpfung mit darauf abgestimmten vernetzt kommunizierenden Sensoren bieten. Diese Art "smarter" Sensoren stellen Dienste innerhalb eines Netzwerks bereit und nutzen Informationen daraus. Dadurch ergibt sich aktuell die Notwendigkeit, die Anforderungen an Prozesssensoren sowie an deren Kommunikationsfähigkeiten detaillierter zu beschreiben – vom einfachen Temperatursensor bis über heute in Entwicklung befindlichen Messsystemen hinaus –, da diese Technologieentwicklungen rasant voranschreiten. Vernetzte Sensoren sind die Voraussetzung für die Realisierung von Cyberphysischen Produktionssystemen (CPPS) und zukünftiger Automatisierungskonzepte für die Prozessindustrie, wie sie auch durch das Zukunftsprojekt "Industrie 4.0" adressiert werden.
Die Technologie-Roadmap liefert darüber hinaus Perspektiven für Forschungs- und Entwicklungsförderung und gibt Ansätze für die Normungsarbeit. Sie wird damit auch für Politik, Industrieverbände und Gremien von Interesse sein. Wenn sich die Exzellenz der Forschung und das ausgeprägte Know-how der Gerätehersteller und Anwender zu Forschungskonsortien auf Augenhöhe zusammentun und das Wissen gemeinsam vorangebracht wird, kommen faire und gut durchdachte Technologietransferprojekte mit Sicherheit zum Erfolg. Neben der technologischen Weiterentwicklung der Prozesssensoren ist von Herstellern und Anwendern die hohe Verfügbarkeit der komplexen Technologie sicherzustellen, damit weiterhin Vertrauen in die Technik besteht – vom Anwender bis ins Management.
From raw ion mobility measurements to disease classification : a comparison of analysis processes
(2015)
Ion mobility spectrometry (IMS) is a technology for the detection of volatile compounds in the air of exhaled breath that is increasingly used in medical applications. One major goal is to classify patients into disease groups, for example diseased versus healthy, from simple breath samples. Raw IMS measurements are data matrices in which peak regions representing the compounds have to be identified and quantified. A typical analysis process consists of pre-processing and peak detection in single experiments, peak clustering to obtain consensus peaks across several experiments, and classification of samples based on the resulting multivariate peak intensities. Recently several automated algorithms for peak detection and peak clustering have been introduced, in order to overcome the current need for human-based analysis that is slow, subjective and sometimes not reproducible. We present an unbiased comparison of a multitude of combinations of peak processing and multivariate classification algorithms on a disease dataset. The specific combination of the algorithms for the different analysis steps determines the classification accuracy, with the encouraging result that certain fully-automated combinations perform even better than current manual approaches.
Continuum physics modeling of tumor growth is a rich topic with room for rather sophisticated models of reaction-transport and mechanics. It also has the attraction of being able to pose and examine solutions to certain questions on tumor growth that are difficult to access using experimental methods alone. However, the imperative of experimental biophysical investigations cannot by understated.
Sunlight has various effects on human health. Several important metabolic processes are only enabled by sunlight. But longtime sun bathing and extended outdoor activities can cause skin irritation, inflammation or even skin cancer due to high radiation dose. We developed in vitro skin models of different complexity to investigate UV-light associated skin damage. Substances and their phototoxic, sun protective or photo-sensitizing potential can be analyzed to prevent white skin cancer.
Unter der Zielsetzung der multimodalen, ortsaufgelösten optischen Spektroskopie für die markierungsfreie Charakterisierung biologischer Materialien nach Morphologie und Chemie werden vier Themenschwerpunkte behandelt.
1. Theorie der elastischen / inelastischen Lichtstreuung und laterale Auflösung in der Mikroskopie
2. Erweiterung eines Raman Mikroskops zu einem multimodalen spektralen Imaging System (MSIS) mit Photonenmigrations-Technologie
3. Erweiterung des MSIS zu Super-Resolution Raman Mikroskopie mit einer Festkörper-Immersionslinse
4. Anwendung des entwickelten MSIS auf biologische Materialien
Block-copolyesters of polyethylene terephthalate (PET) and polyethylene naphthalate (PEN) were synthesized via reactive extrusion. The influence of processing parameters on the material properties on a molecular scale like degree of trans-esterification, block length, and degree of randomness were investigated. The varied process factors were extrusion temperature and rotational speed. The effects of process parameter variation were investigated by 1H-NMR-spectroscopy. The experimental results show a clear dependence of the molecular properties on the processing conditions. By using statistical experimental design (DoE), it was possible to prepare defined copolyesters from PET and PEN without addition of further chemicals. With a degree of randomness between 0.05 and 0.5, the presence of an actual copolyester was confirmed when appropriate extrusion conditions were applied. The reactive extrusion process was confirmed to be suitable to produce defined block-copolyesters in a predictable and reproducible way. It was possible to produce designed sequence lengths, which could be adjusted within a range of 11–136 repeating units in the case of PET and, in the case of PEN, of 2.5–26. The produced materials can be used as barrier materials or barrier coatings to protect substrates against molecular oxygen and water vapour, e.g., in organic photovoltaic applications or food packaging. The described method is a one-pot alternative method to the previously described chemical recycling pathway.
Reflectometry is known since long as an interferometric method which can be used to characterize surfaces and thin films regarding their structure and,to a certain degree,composition as well.Properties like layer structures,layer thickness,density,and interface roughness can be determined by fitting the obtained reflectivity data with an appropriate model using a recursive fitting routine. However,one major drawback of the reflectometric method is its restriction to planar surfaces.In this article we demonstrate an approach to apply X-ray and neutron reflectometry to curved surfaces by means of the example of bent bare and coated glass slides.We prove the possibility to observe all features like Fresnel decay,Kiessig fringes,Bragg peaks and off-specular scattering and are able to interpret the data using common fitting software and to derive quantitative results about roughness,layer thickness and internal structure. The proposed method has become practical due to the availability of high quality 2D-detectors. It opens up the option to explore many kinds and shapes of samples,which,due to their geometry,have not been in the focus of reflectometry techniques until now.
Thin radio-frequency magnetron sputter deposited nano-hydroxyapatite (HA) films were prepared on the surface of a Fe-tricalcium phosphate (Fe-TCP) bioceramic composite, which was obtained using a conventional powder injection moulding technique. The obtained nano-hydroxyapatite coated Fe-TCP biocomposites (nano HA-Fe-TCP) were studied with respect to their chemical and phase composition, surface morphology, water contact angle, surface free energy and hysteresis. The deposition process resulted in a homogeneous, single-phase HA coating. The ability of the surface to support adhesion and the proliferation of human mesenchymal stem cells (hMSCs) was studied using biological short-term tests in vitro. The surface of the uncoated Fe-TCP bioceramic composite showed an initial cell attachment after 24 h of seeding, but adhesion, proliferation and growth did not persist during 14 days of culture.However, the HA-Fe-TCP surfaces allowed cell adhesion, and proliferation during 14 days. The deposition of the nano-HA films on the Fe-TCP surface resulted in higher surface energy, improved hydrophilicity and biocompatibility compared with the surface of the uncoated Fe-TCP. Furthermore, it is suggested that an increase in the polar component of the surface energy was responsible for the enhanced cell adhesion and proliferation in the case of the nano-HA Fe-TCP biocomposites.