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FH Aachen Dimensionen 01/12 Herausgeber : Rektor der FH Aachen Inhaltsverzeichnis Thema 06 Vielfalt integrieren - nachhaltig fördern | Mit einer systematischen Qualitätsentwicklung von Studium und Lehre reagiert die FH Aachen auf den Studienandrang 12 "Wir sprechen niemandem die Studierfähigkeit ab" | Prof. Helmut Jakobs und Dr. Michael Heger äußern sich zur Bildungspolitik und den Herausforderungen der Hochschule in den kommenden Jahren Studium 14 Extraraum für Aachen | NRW-Wissenschaftsministerin Svenja Schulze auf „Hochschul-Tour zum doppelten Abiturjahrgang“ 18 Wohnen auf Zeit | Studierende des Fachbereichs Architektur entwickeln temporäre Wohnformen für die Zeit des Studierendenandrangs 19 Spioniert mein Handy mich aus? | FH-Student Michael Stahl hat eine App geschrieben, die die Internet-Kommunikation seines Smartphones mitschneidet und auswertet 20 Hoch hinaus | FH Aachen entwickelt zusammen mit der Polytechnik- Universität ersten Architekturstudiengang in Namibia 22 Wenn ein Rad ins andere greift | FH Aachen bietet neuen Masterstudiengang „Automatisierungs- und Antriebstechnik“ erstmals im Sommersemester 2012 an 23 Stabiler Lichtbogen | Andreas Bügener testete für eine belgische Firma neuartige Schweißverfahren 24 Student Sven von Osten gewinnt Corporate-Design-Wettbewerb | „Elektromobilität Region Aachen“ hat ein neues Markenzeichen 26 Doppelt gemoppelt hält besser | Studiengang Bauingenieurwesen - Netzingenieur öffnet sich für Handwerksberufe 27 Meldungen / Studium International 28 Erstes Parabolrinnen-Kraftwerk in Thailand | FH-Absolventen waren am Bau der Anlage beteiligt 32 Zirvedekiler | Zwei FH-Professoren befinden sich „in bester Gesellschaft“ 34 Der High-Level-Master für Wirtschaftswissenschaftler | Der OpenBordersMBA punktet mit seiner Internationalität 36 Meldungen / International Forschung 38 Geheimnisvoller Eismond | FH Aachen entwickelt Technik für die Erforschung des Saturnmondes Enceladus 42 Wie ein Blitz | FH-Forscher entwickeln 3400 Grad heißen Plasma-Laser 44 Gegen den Durst | FH entwickelt für Namibia ein mehrstufiges System zur solarthermischen Grundwasseraufbereitung 46 Nachwuchs forscht | FH-Doktoranden präsentieren und diskutieren die Ergebnisse ihrer wissenschaftlichen Arbeit 48 „Global denken – lokal handeln“ | NOWUM-Energy gestaltet lokales Klimaschutzkonzept für Gangelt 49 Meldungen / Forschung Personen 50 „Plötzlich waren vier Kalaschnikows auf mich gerichtet“ | FH-Student Fabian Nawrath war sieben Monate mit dem Fahrrad in Afrika unterwegs 54 Der Ausdauernde | Kanzler Rainer Smeetz geht nach 38 Jahren in Ruhestand 55 Zum 100. Geburtstag von Wernher von Braun | FH veröffentlicht Sonderpublikation mit einem Essay von Prof. Dr. Jesco Freiherr von Puttkamer 56 Der Ingenieur der Phantasia-Welten | FH-Absolvent Ralf-Richard Kenter ist heute Chef des berühmtesten Freizeitparks Deutschlands 58 Verdienter Lohn | 56 Studierende erhalten ein Jahr lang ein Stipendium 60 Ehrenplakettenträger und Absolventen 2011 74 Personalia 76 Buchtipps 77 Neuberufene Professorinnen und Professoren 79 Ausscheidende Professoren 80 Nachwort | Aachener Flugpionier Richard Perlia mit 106 Jahren verstorben Service 82 „Helle Köpfe“ erforschen die Haut des Wassers | Prof. Dr. Günter Jakob Lauth erklärt Viertklässlern, was hinter der Oberflächenspannung steckt 84 Mobile Behörde | Ausländeramt des Kreises Düren bietet neuen Service am Campus Jülich 86 Über die Zukunft der Fachhochschulen | Gemeinsame Veranstaltung von GEW und FH Aachen 87 „Eine faire und transparente Lösung“ | Durch die Einführung flexibler Arbeitszeiten starten Mitarbeiterinnen und Mitarbeiter entspannt in den Arbeitstag 88 Meldungen / Service 90 Messen und Veranstaltungen 94 Ortswechsel / Dreiländereck 95 Impressum
The ”IceMole“ is a novel maneuverable subsurface ice probe for clean in-situ analysis and sampling of subsurface ice and subglacial water/brine. It is developed and build at FH Aachen University of Applied Sciences’ Astronautical Laboratory. A first prototype was successfully tested on the Swiss Morteratsch glacier in 2010. Clean sampling is achieved with a hollow ice screw (as it is used in mountaineering) at the tip of the probe. Maneuverability is achieved with a differentially heated melting head. Funded by the German Space Agency (DLR), a consortium led by FH Aachen currently develops a much more advanced IceMole probe, which includes a sophisticated system for obstacle avoidance, target detection, and navigation in the ice. We intend to use this probe for taking clean samples of subglacial brine at the Blood Falls (McMurdo Dry Valleys, East Antarctica) for chemical and microbiological analysis. In our conference contribution, we 1) describe the IceMole design, 2) report the results of the field tests of the first prototype on the Morteratsch glacier, 3) discuss the probe’s potential for the clean in-situ analysis and sampling of subsurface ice and subglacial liquids, and 4) outline the way ahead in the development of this technology.
Forschungsbericht / Themenheft : Querschnittsthemen 4 Grußwort Prorektorin Prof. Dr. rer. nat. Christiane Vaeßen 6 Highlightprojekte 8 Erfolgsmeldungen aus der Wissenschaft 10 Konstruktion, Planung und Gestaltung / Institut für Baustoffe und Baukonstruktionen (IBB) 12 Stahlbaulabor 13 Geografische Informationssysteme in der Gewässerplanung 14 Didaktisch visuelle Einführung in die Architektur des Aachener Doms 16 CIVITAS-DYN@MO 17 Laserinstallation „fluently scientific“ 18 Subversive Schönheit 19 Gestaltung als Tool Wirtschaftswissenschaften 24 Cross-cultural Training 26 Unternehmerische Orientierung in etablierten Unternehmen – der Einfluss des Top-Management-Führungsstils im internationalen Vergleich 28 LEAN LAB 30 QFD - Stand der Anwendung und Perspektiven in Deutschland 34 Entwicklung eines universellen Qualitätskontrollzentrums 35 Telekommunikationsmärkte der Zukunft MINT 38 Forschungsprojekt GPUFaserVis - Visualisierung von hochauflösenden Nervenfasern des Gehirns 39 "3rd pulse plasma bulb" (quasi-quecksilberfreie HF-Energiesparlampe) 40 Labor für Nuklearchemie 44 CHERNE - Die Erfolgsgeschichte eines Hochschulnetzwerks 46 Steigerung der Immunogenität von therapeutischen Impfstoffen gegen Krebs (INB) 47 Direkter Nachweis von geladenen Makromolekülen mit Feldeffekt-Biosensoren, "veredelt" mit Keramikoberflächen (INB) 48 Smartphones - kleine Alleskönner, die viel über uns wissen 49 Gebrauchstaugliche IT-Systeme für den Mittelstand 51 Engineering-Useability mit Motion-Controllern 52 Labor für Elektrische Antriebssysteme : Rapid-Control-Protoyping von Industrieantrieben 53 Einzelteilfertigung komplexer Endprodukte am Beispiel Zahntechnik und Goldschmiedekunst 55 Schadstoffarme Wasserstoff und Syngas-Verbrennung für die Energieversorgung von morgen 56 EC2GO – Thermomanagement im E-Carsharing 57 SORT Standardised On-Road Test Cycles 58 EIC – Exhaust Impulse Charger 59 Der Blitz – Doch nicht unberechenbar! Ein dynamisches Modell zur Berechnung von Einschlagstellen und Einschlagwahrscheinlichkeiten 60 ETL QUADRAT: Semantische Annotationen in ETL-Prozessen als Qualitäts- und Effizienztreiber für Datenaggregatoren im Internet 61 HiX4AGWS: History-tracing XML for an Actor-driven Grid-enabled Workflow System 62 Impressum
Many tasks for autonomous agents or robots are best described by a specification of the environment and a specification of the available actions the agent or robot can perform. Combining such a specification with the possibility to imperatively program a robot or agent is what we call the actionbased imperative programming. One of the most successful such approaches is Golog. In this paper, we draft a proposal for a new robot programming language YAGI, which is based on the action-based imperative programming paradigm. Our goal is to design a small, portable stand-alone YAGI interpreter. We combine the benefits of a principled domain specification with a clean, small and simple programming language, which does not exploit any side-effects from the implementation language. We discuss general requirements of action-based programming languages and outline YAGI, our action-based language approach which particularly aims at embeddability.
Light-addressable potentiometric sensors (LAPS) are field-effect-based sensors. A modulated light source is used to define the particular measurement spot to perform spatially resolved measurements of chemical species and to generate chemical images. In this work, an organic-LED (OLED) display has been chosen as a light source. This allows high measurement resolution and miniaturisation of the system. A new developed driving method for the OLED display optimised for LAPS-based measurements is demonstrated. The new method enables to define modulation frequencies between 1 kHz and 16 kHz and hence, reduces the measurement time of a chemical image by a factor of 40 compared to the traditional addressing of an OLED display.
Thermodynamic stability, configurational motions and internal forces of haemoglobin (Hb) of three endotherms (platypus, Ornithorhynchus anatinus; domestic chicken, Gallus gallus domesticus and human, Homo sapiens) and an ectotherm (salt water crocodile, Crocodylus porosus) were investigated using circular dichroism, incoherent elastic neutron scattering and coarse-grained Brownian dynamics simulations. The experimental results from Hb solutions revealed a direct correlation between protein resilience, melting temperature and average body temperature of the different species on the 0.1 ns time scale. Molecular forces appeared to be adapted to permit conformational fluctuations with a root mean square displacement close to 1.2 Å at the corresponding average body temperature of the endotherms. Strong forces within crocodile Hb maintain the amplitudes of motion within a narrow limit over the entire temperature range in which the animal lives. In fully hydrated powder samples of human and chicken, Hb mean square displacements and effective force constants on the 1 ns time scale showed no differences over the whole temperature range from 10 to 300 K, in contrast to the solution case. A complementary result of the study, therefore, is that one hydration layer is not sufficient to activate all conformational fluctuations of Hb in the pico- to nanosecond time scale which might be relevant for biological function. Coarse-grained Brownian dynamics simulations permitted to explore residue-specific effects. They indicated that temperature sensing of human and chicken Hb occurs mainly at residues lining internal cavities in the β-subunits.
Chemical imaging systems allow the visualisation of the distribution of chemical species on the sensor surface. This work represents a new flexible approach to read out light-addressable potentiometric sensors (LAPS) with the help of a digital light processing (DLP) set-up. The DLP, known well for video projectors, consists of a mirror-array MEMS device, which allows fast and flexible generation of light patterns. With the help of these light patterns, the sensor surface of the LAPS device can be addressed. The DLP approach has several advantages compared to conventional LAPS set-ups, e.g., the spot size and the shape of the light pointer can be changed easily and no mechanical movement is necessary, which reduces the size of the set-up and increases the stability and speed of the measurement. In addition, the modulation frequency and intensity of the light beam are important parameters of the LAPS set-up. Within this work, the authors will discuss two different ways of light modulation by the DLP set-up, investigate the influence of different modulation frequencies and different light intensities as well as demonstrate the scanning capabilities of the new set-up by pH mapping on the sensor surface.
Visual Virology
(2012)
Upper and lower bound theorems of limit analyses have been presented in part I of the paper. Part II starts with the finite element discretization of these theorems and demonstrates how both can be combined in a primal–dual optimization problem. This recently proposed numerical method is used to guide the development of a new class of closed-form limit loads for circumferential defects, which show that only large defects contribute to plastic collapse with a rapid loss of strength with increasing crack sizes. The formulae are compared with primal–dual FEM limit analyses and with burst tests. Even closer predictions are obtained with iterative limit load solutions for the von Mises yield function and for the Tresca yield function. Pressure loading of the faces of interior cracks in thick pipes reduces the collapse load of circumferential defects more than for axial flaws. Axial defects have been treated in part I of the paper.
Bioconjugates containing the GnRH-III hormone decapeptide as a targeting moiety are able to deliver chemotherapeutic agents specifically to cancer cells expressing GnRH receptors, thereby increasing their local efficacy while limiting the peripheral toxicity. However, the number of GnRH receptors on cancer cells is limited and they desensitize under continuous hormone treatment. A possible approach to increase the receptor mediated tumor targeting and consequently the cytostatic effect of the bioconjugates would be the attachment of more than one chemotherapeutic agent to one GnRH-III molecule. Here we report on the design, synthesis and biochemical characterization of multifunctional bioconjugates containing GnRH-III as a targeting moiety and daunorubicin as a chemotherapeutic agent. Two different drug design approaches were pursued. The first one was based on the bifunctional [4Lys]-GnRH-III (Glp-His-Trp-Lys-His-Asp-Trp-Lys-Pro-Gly-NH2) containing two lysine residues in positions 4 and 8, whose ϵ-amino groups were used for the coupling of daunorubicin. In the second drug design, the native GnRH-III (Glp-His-Trp-Ser-His-Asp-Trp-Lys-Pro-Gly-NH2) was used as a scaffold; an additional lysine residue was coupled to the ϵ-amino group of 8Lys in order to generate two free amino groups available for conjugation of daunorubicin. The in vitro stability/degradation of all synthesized compounds was investigated in human serum, as well as in the presence of rat liver lysosomal homogenate. Their cellular uptake was determined on human breast cancer cells and the cytostatic effect was evaluated on human breast, colon and prostate cancer cell lines. Compared with a monofunctional compound, both drug design approaches resulted in multifunctional bioconjugates with increased cytostatic effect.
In this article, we report on the heat-transfer resistance at interfaces as a novel, denaturation-based method to detect single-nucleotide polymorphisms in DNA. We observed that a molecular brush of double-stranded DNA grafted onto synthetic diamond surfaces does not notably affect the heat-transfer resistance at the solid-to-liquid interface. In contrast to this, molecular brushes of single-stranded DNA cause, surprisingly, a substantially higher heat-transfer resistance and behave like a thermally insulating layer. This effect can be utilized to identify ds-DNA melting temperatures via the switching from low- to high heat-transfer resistance. The melting temperatures identified with this method for different DNA duplexes (29 base pairs without and with built-in mutations) correlate nicely with data calculated by modeling. The method is fast, label-free (without the need for fluorescent or radioactive markers), allows for repetitive measurements, and can also be extended toward array formats. Reference measurements by confocal fluorescence microscopy and impedance spectroscopy confirm that the switching of heat-transfer resistance upon denaturation is indeed related to the thermal on-chip denaturation of DNA.
Betriebskostenabrechnung - Die Pflicht des Vermieters zur Beachtung des Wirtschaftlichkeitsgebots
(2012)
Mit seiner aktuellen Entscheidung (BGH v. 6.11.2011 – VIII ZR 340/10, MDR 2011, 1095 = MietRB MDR 2011, 337) hat der BGH die Darlegungs- und Beweislast für einen Verstoß gegen das Gebot der Wirtschaftlichkeit bei der Abrechnung von Betriebskosten konkretisiert. Der Beitrag erläutert anhand der Hintergründe des Gebotes der Wirtschaftlichkeit die Konsequenzen für die Praxis.
Label-free electrical detection of consecutive deoxyribonucleic acid (DNA) hybridization/denaturation by means of an array of individually addressable field-effect-based nanoplate silicon-on-insulator (SOI) capacitors modified with gold nanoparticles (Au-NP) is investigated. The proposed device detects charge changes on Au-NP/DNA hybrids induced by the hybridization or denaturation event. DNA hybridization was performed in a high ionic-strength solution to provide a high hybridization efficiency. On the other hand, to reduce the screening of the DNA charge by counter ions and to achieve a high sensitivity, the sensor signal induced by the hybridization and denaturation events was measured in a low ionic-strength solution. High sensor signals of about 120, 90, and 80 mV were registered after the DNA hybridization, denaturation, and re-hybridization events, respectively. Fluorescence microscopy has been applied as reference method to verify the DNA immobilization, hybridization, and denaturation processes. An electrostatic charge-plane model for potential changes at the gate surface of a nanoplate field-effect sensor induced by the DNA hybridization has been developed taking into account both the Debye length and the distance of the DNA charge from the gate surface.
Smartphone Forensik
(2012)
Suburethral slings as well as different meshes are widely used treating stress urinary incontinence and prolaps in women. With the development of MiniSlings and special meshes using less alloplastic material anchorage systems become more important to keep devices in place and to put some tension especially on the MiniSlings. To date, there are many different systems of MiniSlings of different companies on the market which differ in the structure of the used meshes and anchors. A new objective measurement method to compare different properties of MiniSling systems (mesh and anchor) is presented in this article. Ballistic gelatine acts as soft tissue surrogate. Significant differences in parameters like pull-out strength of anchors or shrinkage of meshes under loading conditions have been determined. The form and size of the anchors as well as the structural stability of the meshes are decisive for a proper integration. The tested anchorings sytems showed markedly different mechanical function at their respective load bearing capacity. As the stable fixation of the device in tissue is a prerequisite for a permanet reinforcement, the proposed test system permits further optimisation of anchor and mesh devices to improve the success of the surgical treatment
Two types of microvalves based on temperature-responsive poly(N-isopropylacrylamide) (PNIPAAm) and pH-responsive poly(sodium acrylate) (PSA) hydrogel films have been developed and tested. The PNIPAAm and PSA hydrogel films were prepared by means of in situ photopolymerization directly inside the fluidic channel of a microfluidic chip fabricated by combining Si and SU-8 technologies. The swelling/shrinking properties and height changes of the PNIPAAm and PSA films inside the fluidic channel were studied at temperatures of deionized water from 14 to 36 °C and different pH values (pH 3–12) of Titrisol buffer, respectively. Additionally, in separate experiments, the lower critical solution temperature (LCST) of the PNIPAAm hydrogel was investigated by means of a differential scanning calorimetry (DSC) and a surface plasmon resonance (SPR) method. Mass-flow measurements have shown the feasibility of the prepared hydrogel films to work as an on-chip integrated temperature- or pH-responsive microvalve capable to switch the flow channel on/off.
Die bauaufsichtliche Einführung der Eurocodes steht unmittelbar bevor. Für den Bereich des Stahl- und Spannbetonbaus soll die Anwendung zum 1. Juli 2012 verbindlich sein, d. h. mit diesem Stichtag sollte nur noch der Eurocode 2 (DIN EN 1992-1-1, Ausgabe Januar 2011) mit seinem zugehörigen nationalen Anhang (DIN EN 1992-1-1/NA, Ausgabe Januar 2011) Verwendung finden, die DIN 1045-1 wird zurückgezogen. Bereits seit März 2010 gilt eine Übergangsphase, ist der die Anwendung des Eurocodes alternativ zur DIN 1045-1 als bauaufsichtlich gleichwertige Lösung möglich.
Beton nach DIN 1045-2
(2012)
Geotechnik
(2012)
In der nationalen und der europäischen Normung werden die geotechnischen Aufgaben zwecks Mindestanforderungen an Baugrunduntersuchung, rechnerische Nachweise und Überwachung der Ausführung in drei Klassen (Kategorien) eingeteilt. Sie richten sich nach der zu erwartenden Reaktion des Baugrundes, nach dem geotechnischen Schwierigkeitsgrad des Tragwerks und seiner Einflüsse auf dieUmgebung.
Siedlungswasserwirtschaft
(2012)
Abfallwirtschaft
(2012)
Stahlbau
(2012)
Thin films of poly(ethyleneterephthalate) [PET]were exposed to radiation dose ranging from 10 to 30 kGy by using gamma rays in the range 12.8-177.8 MGy using swift light ions of hydrogen. There was no effect of the radiation dose on the optical behaviour of PET as a result of exposure to radiation dose up to 30 kGy brought about by gamma rays but a significant decrease in the optical band gap values was observed when PET was exposed to swift light ions of hydrogen. The data obtained are discussed in terms of optical studies carried out on PET using swift heavy ions.
Die Detektion von Schadstoffen repräsentiert in der Umweltanalytik eine wichtige Aufgabenstellung. Gerade die Abwasser- bzw. Brauchwasseranalytik sowie die Prozesskontrolle haben einen hohen Stellenwert. Siliziumbasierte Dünnschichtsensoren bieten eine kostengünstige Möglichkeit, „online“-Messungen bzw. Vor-Ort-Messungen zeitnah durchzuführen. In dieser Arbeit wird ein potentiometrisches Sensorarray auf der Basis von Chalkogenidgläsern zur Detektion von Schwermetallen in wässrigen Medien vorgestellt.
An increasing number of applications target their executions on specific hardware like general purpose Graphics Processing Units. Some Cloud Computing providers offer this specific hardware so that organizations can rent such resources. However, outsourcing the whole application to the Cloud causes avoidable costs if only some parts of the application benefit from the specific expensive hardware. A partial execution of applications in the Cloud is a tradeoff between costs and efficiency. This paper addresses the demand for a consistent framework that allows for a mixture of on- and off-premise calculations by migrating only specific parts to a Cloud. It uses the concept of workflows to present how individual workflow tasks can be migrated to the Cloud whereas the remaining tasks are executed on-premise.
The impact of surgical staplers on tissues has been studied mostly in an empirical manner. In this paper, finite element method was used to clarify the mechanics of tissue stapling and associated phenomena. Various stapling modalities and several designs of circular staplers were investigated to evaluate the impact of the device on tissues and mechanical performance of the end-to-end colorectal anastomosis. Numerical simulations demonstrated that a single row of staples is not adequate to resist leakage due to non-linear buckling and opening of the tissue layers between two adjacent staples. Compared to the single staple row configuration, significant increase in stress experienced by the tissue at the inner staple rows was observed in two and three rows designs. On the other hand, adding second and/or third staple row had no effect on strain in the tissue inside the staples. Variable height design with higher staples in outer rows significantly reduced the stresses and strains in outer rows when compared to the same configuration with flat cartridge.
Influence of a freeze–thaw cycle on the stress–stretch curves of tissues of porcine abdominal organs
(2012)
The paper investigates both fresh porcine spleen and liver and the possible decomposition of these organs under a freeze–thaw cycle. The effect of tissue preservation condition is an important factor which should be taken into account for protracted biomechanical tests. In this work, tension tests were conducted for a large number of tissue specimens from twenty pigs divided into two groups of 10. Concretely, the first group was tested in fresh state; the other one was tested after a freeze-thaw cycle which simulates the conservation conditions before biomechanical experiments. A modified Fung model for isotropic behavior was adopted for the curve fitting of each kind of tissues. Experimental results show strong effects of the realistic freeze–thaw cycle on the capsule of elastin-rich spleen but negligible effects on the liver which virtually contains no elastin. This different behavior could be explained by the autolysis of elastin by elastolytic enzymes during the warmer period after thawing. Realistic biomechanical properties of elastin-rich organs can only be expected if really fresh tissue is tested. The observations are supported by tests of intestines.
Purpose: It was demonstrated previously that retinal pulse wave velocity (rPWV) as a measure of retinal arterial stiffness is increased in aged anamnestically healthy volunteers compared with young healthy subjects. Using novel methodology of rPWV assessment this finding was confirmed and investigated whether it might relate to the increased blood pressure usually accompanying the aging process, rather than to the aging itself.
Methods: A total of 12 young 25.5-year-old (24.0–28.8) [median(1st quartile–3rd quartile)] and 12 senior 68.5-year-old (63.8–71.8) anamnestically healthy volunteers; and 12 senior 63.0-year-old (60.8–65.0) validated healthy volunteers and 12 young 33.0-year-old (29.5–35.0) hypertensive patients were examined. Time-dependent alterations of vessel diameter were assessed by the Dynamic Vessel Analyzer in a retinal artery of each subject. The data were filtered and processed using mathematical signal analysis and rPWVs were calculated.
Results: rPWV amounted to 1200 (990-1470) RU (relative units)/s in the hypertensive group and to 1040 (700-2230) RU/s in anamnestically healthy seniors. These differed significantly from rPWVs in young healthy group (410 [280–500] RU/s) and in validated healthy seniors (400 [320–510] RU/s). rPWV associated with age and mean arterial pressure (MAP) in the pooled cohort excluded validated healthy seniors. In a regression model these associations remain when alternately adjusted for MAP and age. When including validated healthy seniors in the pooled cohort only association with MAP remains.
Conclusions: Both aging (with not excluded cardiovascular risk factors) and mild hypertension are associated with elevated rPWV. rPWV increases to a similar extent both in young mildly hypertensive subjects and in aged anamnestically healthy persons. Healthy aging is not associated with increased rPWV.
It is well known that the already large dielectric constants of some electrolytes like BaTiO₃ can be enhanced further by adding metallic (e.g. Ni, Cu or Ag) nanoparticles. The enhancement can be quite large, a factor of more than 1000 is possible. The consequences for the properties will be discussed in the present paper applying a brick-layer model (BLM) for calculating dc-resistivities of thin layers and a modified one (PBLM) that includes percolation for calculating dielectric properties of these materials. The PBLM results in an at least qualitative description and understanding of the physical phenomena: This model gives an explanation for the steep increase of the dielectric constant below the percolation threshold and why this increase is connected to a dramatic decrease of the breakdown voltage as well as the ability of storing electrical energy. We conclude that metallic electrolyte composites like BaTiO₃ are not appropriate for energy storage.
Im Beitrag wird zunächst das Verfahren eines dynamischen elektro-geometrischen Modells vorgestellt. Dieses arbeitet im Gegensatz zum klassischen Blitzkugel-Verfahren nicht mit konstanten Radien; vielmehr wird der Radius der Blitzkugel variiert. Dabei werden ausschließlich vorhandene und in internationalen Normen anerkannte Ergebnisse, blitzphysikalische Grundlagen und Untersuchungen verwendet, und auf deren Grundlage ein numerisches Verfahren erarbeitet. Mit dem dynamischen elektro-geometrischen Modell werden dann einige Beispiele des Schutzes mit Fangstangen, die gemäß dem klassischen Blitzkugel-Verfahren nach DIN EN 62305-3 für die Schutzklassen I – II – III – IV geplant sind, untersucht. Es wird gezeigt, dass die Einfangwirksamkeiten wesentlich höher sind als in der Normenreihe DIN EN 62305 selbst angegeben. Grund dafür ist die Tatsache, dass das Blitzkugel-Verfahren sehr konservativ aufgebaut ist und dem Planer von Blitzschutzsystemen nur die möglichen Stellen für einen Einschlag aufzeigt, ohne eine Bewertung der Einschlagshäufigkeit zu liefern. Andererseits bedeutet dies jedoch, dass man mit dem klassischen Blitzkugel-Verfahren stets auf der „sicheren Seite“ liegt.
Cell-based sensors for the detection of gases have long been underrepresented, due to the cellular requirement of being cultured in a liquid environment. In this work we established a cell-based gas biosensor for the detection of toxic substances in air, by adapting a commercial sensor chip (Bionas®), previously used for the measurement of pollutants in liquids. Cells of the respiratory tract (A549, RPMI 2650, V79), which survive at a gas phase in a natural context, are used as biological receptors. The physiological cell parameters acidification, respiration and morphology are continuously monitored in parallel. Ammonia was used as a highly water-soluble model gas to test the feasibility of the sensor system. Infrared measurements confirmed the sufficiency of the medium draining method. This sensor system provides a basis for many sensor applications such as environmental monitoring, building technology and public security.
Im Folgenden sollen Anlass und Inhalt einer Due Diligence erläutert werden. Im Rahmen einer Checkliste werden Beratern und Unternehmen Hinweise zu möglichen Prüfungsgebieten sowie zu vorzuhaltenden oder zu prüfenden Unterlagen gegeben. Entstanden ist die Checkliste aus der langjährigen praktischen Tätigkeit der Autoren bei einer großen Wirtschaftsprüfungsgesellschaft bzw. einer deutschen Großbank.