@article{KirchhofKraft2012, author = {Kirchhof, Michael and Kraft, Bodo}, title = {Hybrides Vorgehensmodell : Agile und klassische Methoden im Projekt passend kombinieren}, series = {ProjektMagazin}, journal = {ProjektMagazin}, number = {11}, publisher = {Berleb Media}, address = {Taufkirchen}, pages = {11 Seiten}, year = {2012}, abstract = {Agil ist im Trend und immer mehr Unternehmen, die ihre Projekte bisher nach klassischen Prinzipien durchf{\"u}hrten, denken {\"u}ber den Einsatz agiler Methoden nach. Doch selbst wenn die Organisation bereits beide Philosophien unterst{\"u}tzt, gilt f{\"u}r ein Projekt meist die klare Vorgabe: agil oder klassisch. Es gibt aber noch einen anderen Ansatz, mit diesen "unterschiedlichen Welten" umzugehen: Und zwar die beiden Philosophien innerhalb eines Projekts zu kombinieren. Wie dies in der Praxis aussehen und gelingen kann, zeigen Dr. Michael Kirchhof und Prof. Dr. Bodo Kraft in diesem Beitrag.}, language = {de} } @article{SchoeningBaecker2012, author = {Sch{\"o}ning, Michael Josef and B{\"a}cker, Matthias}, title = {Chip-basierte Sensoren f{\"u}r die Biotechnik}, volume = {13}, number = {2}, publisher = {BIOCOM}, address = {Berlin}, issn = {1611-0854}, pages = {4 Seiten}, year = {2012}, language = {de} } @article{HasanKeilStaatetal.2012, author = {Hasan, Istabrak and Keil, Ludger and Staat, Manfred and Wahl, Gerhard and Bourauel, Christoph}, title = {Determination of the frictional coefficient of the implant-antler interface : experimental approach}, series = {Biomedical Engineering / Biomedizinische Technik}, volume = {57}, journal = {Biomedical Engineering / Biomedizinische Technik}, number = {5}, publisher = {De Gruyter}, address = {Berlin}, issn = {1862-278X}, pages = {359 -- 363}, year = {2012}, abstract = {The similar bone structure of reindeer antler to human bone permits studying the osseointegration of dental implants in the jawbone. As the friction is one of the major factors that have a significant influence on the initial stability of immediately loaded dental implants, it is essential to define the frictional coefficient of the implant-antler interface. In this study, the kinetic frictional forces at the implant-antler interface were measured experimentally using an optomechanical setup and a stepping motor controller under different axial loads and sliding velocities. The corresponding mean values of the static and kinetic frictional coefficients were within the range of 0.5-0.7 and 0.3-0.5, respectively. An increase in the frictional forces with increasing applied axial loads was registered. The measurements showed an evidence of a decrease in the magnitude of the frictional coefficient with increasing sliding velocity. The results of this study provide a considerable assessment to clarify the suitable frictional coefficient to be used in the finite element contact analysis of antler specimens.}, language = {en} } @article{BassamHeschelerTemizArtmannetal.2012, author = {Bassam, Rasha and Hescheler, J{\"u}rgen and Temiz Artmann, Ayseg{\"u}l and Artmann, Gerhard and Digel, Ilya}, title = {Effects of spermine NONOate and ATP on the thermal stability of hemoglobin}, series = {BMC Biophysics}, volume = {5}, journal = {BMC Biophysics}, publisher = {BioMed Central}, address = {London}, issn = {2046-1682}, doi = {10.1186/2046-1682-5-16}, year = {2012}, abstract = {Background Minor changes in protein structure induced by small organic and inorganic molecules can result in significant metabolic effects. The effects can be even more profound if the molecular players are chemically active and present in the cell in considerable amounts. The aim of our study was to investigate effects of a nitric oxide donor (spermine NONOate), ATP and sodium/potassium environment on the dynamics of thermal unfolding of human hemoglobin (Hb). The effect of these molecules was examined by means of circular dichroism spectrometry (CD) in the temperature range between 25°C and 70°C. The alpha-helical content of buffered hemoglobin samples (0.1 mg/ml) was estimated via ellipticity change measurements at a heating rate of 1°C/min. Results Major results were: 1) spermine NONOate persistently decreased the hemoglobin unfolding temperature T u irrespectively of the Na + /K + environment, 2) ATP instead increased the unfolding temperature by 3°C in both sodium-based and potassium-based buffers and 3) mutual effects of ATP and NO were strongly influenced by particular buffer ionic compositions. Moreover, the presence of potassium facilitated a partial unfolding of alpha-helical structures even at room temperature. Conclusion The obtained data might shed more light on molecular mechanisms and biophysics involved in the regulation of protein activity by small solutes in the cell.}, language = {en} } @article{Grotendorst2012, author = {Grotendorst, Johannes}, title = {Supercomputer programmieren - ein besonderes Studienangebot in J{\"u}lich}, series = {Junge Wissenschaft}, volume = {27}, journal = {Junge Wissenschaft}, number = {94}, publisher = {Verlag Junge Wissenschaft}, address = {D{\"u}sseldorf}, isbn = {0179-8529}, pages = {12 -- 14}, year = {2012}, language = {de} } @article{StaatVu2012, author = {Staat, Manfred and Vu, Duc Khoi}, title = {Limit analysis of flaws in pressurized pipes and cylindrical vessels Part II: Circumferential defects}, series = {Engineering Fracture Mechanic}, volume = {97}, journal = {Engineering Fracture Mechanic}, number = {1}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0013-7944}, doi = {10.1016/j.engfracmech.2012.05.017}, pages = {314 -- 333}, year = {2012}, abstract = {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.}, language = {en} } @article{Grotendorst2012, author = {Grotendorst, Johannes}, title = {IAS Winter School: Hierarchical Methods for Dynamics in Complex Molecular Systems}, series = {Innovatives Supercomputing in Deutschland : inSiDE}, volume = {10}, journal = {Innovatives Supercomputing in Deutschland : inSiDE}, publisher = {HLRS}, address = {Stuttgart}, pages = {104 -- 1}, year = {2012}, language = {en} } @article{LustfeldPithanReissel2012, author = {Lustfeld, Hans and Pithan, C. and Reißel, Martin}, title = {Metallic electrolyte composites in the framework of the brick-layer model}, series = {Journal of the European Ceramic Society}, volume = {32}, journal = {Journal of the European Ceramic Society}, number = {4}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0955-2219}, doi = {10.1016/j.jeurceramsoc.2011.10.017}, pages = {859 -- 864}, year = {2012}, abstract = {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.}, language = {en} } @article{MansurovDigelBiisenbaevetal.2012, author = {Mansurov, Zulkhair A. and Digel, Ilya and Biisenbaev, M. and Savistkaya, I. and Kistaubaeva, Aida and Akimbekov, Nuraly S. and Zhubanova, Azhar Achmet}, title = {Bio-composite material on the basis of carbonized rice husk in biomedicine and environmental applications}, series = {Eurasian Chemico-Technological Journal}, volume = {14}, journal = {Eurasian Chemico-Technological Journal}, number = {2}, publisher = {Institute of Combustion Problems}, address = {Almaty}, issn = {2522-4867}, doi = {10.18321/ectj105}, pages = {115 -- 131}, year = {2012}, language = {en} } @article{BohrnStuetzFuchsetal.2012, author = {Bohrn, Ulrich and St{\"u}tz, Evamaria and Fuchs, Karen and Fleischer, M. and Sch{\"o}ning, Michael Josef and Wagner, P.}, title = {Monitoring of irritant gas using a whole-cell-based sensor system}, series = {Sensors and Actuators B: Chemical}, volume = {175}, journal = {Sensors and Actuators B: Chemical}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0925-4005}, doi = {10.1016/j.snb.2012.05.088}, pages = {208 -- 217}, year = {2012}, abstract = {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.}, language = {en} } @article{BaeckerRaueSchusseretal.2012, author = {B{\"a}cker, Matthias and Raue, Markus and Schusser, Sebastian and Jeitner, C. and Breuer, Lars and Wagner, P. and Poghossian, Arshak and F{\"o}rster, Arnold and Mang, Thomas and Sch{\"o}ning, Michael Josef}, title = {Microfluidic chip with integrated microvalves based on temperature- and pH-responsive hydrogel thin films}, series = {Physica Status Solidi (a)}, volume = {209}, journal = {Physica Status Solidi (a)}, number = {5}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1862-6319}, doi = {10.1002/pssa.201100763}, pages = {839 -- 845}, year = {2012}, abstract = {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.}, language = {en} }