@article{BaeckerKochEibenetal.2017, author = {B{\"a}cker, Matthias and Koch, Claudia and Eiben, Sabine and Geiger, Fania and Eber, Fabian and Gliemann, Hartmut and Poghossian, Arshak and Wege, Christina and Sch{\"o}ning, Michael Josef}, title = {Tobacco mosaic virus as enzyme nanocarrier for electrochemical biosensors}, series = {Sensors and Actuators B: Chemical}, volume = {238}, journal = {Sensors and Actuators B: Chemical}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0925-4005}, doi = {10.1016/j.snb.2016.07.096}, pages = {716 -- 722}, year = {2017}, abstract = {The conjunction of (bio-)chemical recognition elements with nanoscale biological building blocks such as virus particles is considered as a very promising strategy for the creation of biohybrids opening novel opportunities for label-free biosensing. This work presents a new approach for the development of biosensors using tobacco mosaic virus (TMV) nanotubes or coat proteins (CPs) as enzyme nanocarriers. Sensor chips combining an array of Pt electrodes loaded with glucose oxidase (GOD)-modified TMV nanotubes or CP aggregates were used for amperometric detection of glucose as a model system for the first time. The presence of TMV nanotubes or CPs on the sensor surface allows binding of a high amount of precisely positioned enzymes without substantial loss of their activity, and may also ensure accessibility of their active centers for analyte molecules. Specific and efficient immobilization of streptavidin-conjugated GOD ([SA]-GOD) complexes on biotinylated TMV nanotubes or CPs was achieved via bioaffinity binding. These layouts were tested in parallel with glucose sensors with adsorptively immobilized [SA]-GOD, as well as [SA]-GOD crosslinked with glutardialdehyde, and came out to exhibit superior sensor performance. The achieved results underline a great potential of an integration of virus/biomolecule hybrids with electronic transducers for future applications in biosensorics and biochips.}, language = {en} } @article{HeinzeMangPopescuetal.2016, author = {Heinze, D. and Mang, Thomas and Popescu, C. and Weichold, O.}, title = {Effect of side chain length and degree of polymerization on the decomposition and crystallization behaviour of chlorinated poly(vinyl ester) oligomers}, series = {Thermochimica Acta}, volume = {637}, journal = {Thermochimica Acta}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0040-6031 (electronic)}, doi = {10.1016/j.tca.2016.05.015}, pages = {143 -- 153}, year = {2016}, abstract = {Four members of a homologous series of chlorinated poly(vinyl ester) oligomers CCl₃-(CH₂CH (OCO(CH₂)ₘCH₃))ₙ-Cl with degrees of polymerization of 10 and 20 were prepared by telomerisation using carbon tetrachloride. The number of side chain carbon atoms ranges from 2 (poly(vinyl acetate) to 18 (poly(vinyl stearate)). The effect of the n-alkyl side chain length and of the degree of polymerization on the thermal stability and crystallization behaviour of the synthesized compounds was investigated. All oligomers degrade in two major steps by first losing HCl and side chains with subsequent breakdown of the backbone. The members with short side chains, up to poly(vinyl octanoate), are amorphous and show internal plasticization, whereas those with high number of side chain carbon atoms are semi-crystalline due to side-chain crystallization. A better packing for poly(vinyl stearate) is also noticeable. The glass transition and melting temperatures as well as the onset temperature of decomposition are influenced to a larger extent by the side chain length than by the degree of polymerization. Thermal stability is improved if both the size and number of side chains increase, but only a long side chain causes a significant increase of the resistance to degradation. This results in a stabilization of PVAc so that oligomers from poly(vinyl octanoate) on are stable under atmospheric conditions. Thus, the way to design stable, chlorinated PVEs oligomers is to use a long n-alkyl side chain.}, language = {en} } @article{HaagZontarSchleupenetal.2014, author = {Haag, S. and Zontar, D. and Schleupen, Josef and M{\"u}ller, T. and Brecher, C.}, title = {Chain of refined perception in self-optimizing assembly of micro-optical systems}, series = {Journal of sensors and sensor systems}, volume = {3}, journal = {Journal of sensors and sensor systems}, number = {1}, publisher = {Copernicus Publ.}, address = {G{\"o}ttingen}, issn = {2194-878X}, doi = {10.5194/jsss-3-87-2014}, pages = {87 -- 95}, year = {2014}, abstract = {Today, the assembly of laser systems requires a large share of manual operations due to its complexity regarding the optimal alignment of optics. Although the feasibility of automated alignment of laser optics has been shown in research labs, the development effort for the automation of assembly does not meet economic requirements - especially for low-volume laser production. This paper presents a model-based and sensor-integrated assembly execution approach for flexible assembly cells consisting of a macro-positioner covering a large workspace and a compact micromanipulator with camera attached to the positioner. In order to make full use of available models from computer-aided design (CAD) and optical simulation, sensor systems at different levels of accuracy are used for matching perceived information with model data. This approach is named "chain of refined perception", and it allows for automated planning of complex assembly tasks along all major phases of assembly such as collision-free path planning, part feeding, and active and passive alignment. The focus of the paper is put on the in-process image-based metrology and information extraction used for identifying and calibrating local coordinate systems as well as the exploitation of that information for a part feeding process for micro-optics. Results will be presented regarding the processes of automated calibration of the robot camera as well as the local coordinate systems of part feeding area and robot base.}, language = {en} } @article{ValeroBung2016, author = {Valero, Daniel and Bung, Daniel Bernhard}, title = {Sensitivity of turbulent Schmidt number and turbulence model to simulations of jets in crossflow}, series = {Environmental Modelling and Software}, volume = {82}, journal = {Environmental Modelling and Software}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1364-8152 (electronic)}, doi = {10.1016/j.envsoft.2016.04.030}, pages = {218 -- 228}, year = {2016}, abstract = {Environmental discharges have been traditionally designed by means of cost-intensive and time-consuming experimental studies. Some extensively validated models based on an integral approach have been often employed for water quality problems, as recommended by USEPA (i.e.: CORMIX). In this study, FLOW-3D is employed for a full 3D RANS modelling of two turbulent jet-to-crossflow cases, including free surface jet impingement. Results are compared to both physical modelling and CORMIX to better assess model performance. Turbulence measurements have been collected for a better understanding of turbulent diffusion's parameter sensitivity. Although both studied models are generally able to reproduce jet trajectory, jet separation downstream of the impingement has been reproduced only by RANS modelling. Additionally, concentrations are better reproduced by FLOW-3D when the proper turbulent Schmidt number is used. This study provides a recommendation on the selection of the turbulence model and the turbulent Schmidt number for future outfall structures design studies.}, language = {en} } @article{JablonowskiKollmannNabeletal.2016, author = {Jablonowski, Nicolai David and Kollmann, Tobias and Nabel, Moritz and Damm, Tatjana and Klose, Holger and M{\"u}ller, Michael and Bl{\"a}sing, Marc and Seebold, S{\"o}ren and Krafft, Simone and Kuperjans, Isabel and Dahmen, Markus and Schurr, Ulrich}, title = {Valorization of Sida (Sida hermaphrodita) biomass for multiple energy purposes}, series = {GCB [Global Change Biology] Bioenergy}, volume = {9}, journal = {GCB [Global Change Biology] Bioenergy}, number = {1}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1757-1707 (online)}, doi = {10.1111/gcbb.12346}, pages = {202 -- 214}, year = {2016}, abstract = {The performance and biomass yield of the perennial energy plant Sida hermaphrodita (hereafter referred to as Sida) as a feedstock for biogas and solid fuel was evaluated throughout one entire growing period at agricultural field conditions. A Sida plant development code was established to allow comparison of the plant growth stages and biomass composition. Four scenarios were evaluated to determine the use of Sida biomass with regard to plant development and harvest time: (i) one harvest for solid fuel only; (ii) one harvest for biogas production only; (iii) one harvest for biogas production, followed by a harvest of the regrown biomass for solid fuel; and (iv) two consecutive harvests for biogas production. To determine Sida's value as a feedstock for combustion, we assessed the caloric value, the ash quality, and melting point with regard to DIN EN ISO norms. The results showed highest total dry biomass yields of max. 25 t ha⁻¹, whereas the highest dry matter of 70\% to 80\% was obtained at the end of the growing period. Scenario (i) clearly indicated the highest energy recovery, accounting for 439 288 MJ ha⁻¹; the energy recovery of the four scenarios from highest to lowest followed this order: (i) ≫ (iii) ≫ (iv) > (ii). Analysis of the Sida ashes showed a high melting point of >1500 °C, associated with a net calorific value of 16.5-17.2 MJ kg⁻¹. All prerequisites for DIN EN ISO norms were achieved, indicating Sida's advantage as a solid energy carrier without any post-treatment after harvesting. Cell wall analysis of the stems showed a constant lignin content after sampling week 16 (July), whereas cellulose had already reached a plateau in sampling week 4 (April). The results highlight Sida as a promising woody, perennial plant, providing biomass for flexible and multipurpose energy applications.}, language = {en} } @article{GhoschBaierSchuetzetal.2016, author = {Ghosch, S. and Baier, M. and Sch{\"u}tz, J. and Schneider, Felix and Scherer, Ulrich W.}, title = {Analysis of electronic autoradiographs by mathematical post-processing}, series = {Radiation Effects and Defects in Solids: Incorporating plasma science and plasma technology}, volume = {171}, journal = {Radiation Effects and Defects in Solids: Incorporating plasma science and plasma technology}, number = {1-2}, publisher = {Taylor \& Francis}, address = {London}, issn = {1029-4953}, doi = {10.1080/10420150.2016.1155587}, pages = {161 -- 172}, year = {2016}, abstract = {Autoradiography is a well-established method of nuclear imaging. When different radionuclides are present simultaneously, additional processing is needed to distinguish distributions of radionuclides. In this work, a method is presented where aluminium absorbers of different thickness are used to produce images with different cut-off energies. By subtracting images pixel-by-pixel one can generate images representing certain ranges of β-particle energies. The method is applied to the measurement of irradiated reactor graphite samples containing several radionuclides to determine the spatial distribution of these radionuclides within pre-defined energy windows. The process was repeated under fixed parameters after thermal treatment of the samples. The greyscale images of the distribution after treatment were subtracted from the corresponding pre-treatment images. Significant changes in the intensity and distribution of radionuclides could be observed in some samples. Due to the thermal treatment parameters the most significant differences were observed in the ³H and ¹⁴C inventory and distribution.}, language = {en} } @article{ValeroBung2016, author = {Valero, Daniel and Bung, Daniel Bernhard}, title = {Development of the interfacial air layer in the non-aerated region of high-velocity spillway flows: Instabilities growth, entrapped air and influence on the self-aeration onset}, series = {International Journal of Multiphase Flow}, volume = {84}, journal = {International Journal of Multiphase Flow}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0301-9322}, doi = {10.1016/j.ijmultiphaseflow.2016.04.012}, pages = {66 -- 74}, year = {2016}, abstract = {Self-aeration is traditionally explained by the water turbulent boundary layer outer edge intersection with the free surface. This paper presents a discussion on the commonly accepted hypothesis behind the computation of the critical point of self-aeration in spillway flows and a new formulation is proposed based on the existence of a developing air flow over the free surface. Upstream of the inception point of self-aeration, some surface roughening has been often reported in previous studies which consequently implies some entrapped air transport and air-water flows coupling. Such air flow is proven in this study by presenting measured air velocities and computing the air boundary layer thickness for a 1V:2H smooth chute flow. Additionally, the growth rate of free surface waves has been analysed by means of Ultrasonic Sensors measurements, obtaining also the entrapped air concentration. High-speed camera imaging has been used for qualitative study of the flow perturbations.}, language = {en} } @article{MolinnusSorichBartzetal.2016, author = {Molinnus, Denise and Sorich, Maren and Bartz, Alexander and Siegert, Petra and Willenberg, Holger S. and Lisdat, Fred and Poghossian, Arshak and Keusgen, Michael and Sch{\"o}ning, Michael Josef}, title = {Towards an adrenaline biosensor based on substrate recycling amplification in combination with an enzyme logic gate}, series = {Sensors and Actuators B: Chemical}, volume = {237}, journal = {Sensors and Actuators B: Chemical}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0925-4005}, doi = {10.1016/j.snb.2016.06.064}, pages = {190 -- 195}, year = {2016}, abstract = {An amperometric biosensor using a substrate recycling principle was realized for the detection of low adrenaline concentrations (1 nM) by measurements in phosphate buffer and Ringer's solution at pH 6.5 and pH 7.4, respectively. In proof-of-concept experiments, a Boolean logic-gate principle has been applied to develop a digital adrenaline biosensor based on an enzyme AND logic gate. The obtained results demonstrate that the developed digital biosensor is capable for a rapid qualitative determination of the presence/absence of adrenaline in a YES/NO statement. Such digital biosensor could be used in clinical diagnostics for the control of a correct insertion of a catheter in the adrenal veins during adrenal venous-sampling procedure.}, language = {en} } @article{KnobeGiesenPlateetal.2016, author = {Knobe, M. and Giesen, M. and Plate, S. and Gradl-Dietsch, G. and Buecking, B. and Eschbach, D. and Laack, Walter van and Pape, H.-C.}, title = {The Aachen mobility and balance index to measure physiological falls risk: a comparison with the Tinetti POMA scale}, series = {European Journal Of Trauma And Emergency Surgery}, volume = {42}, journal = {European Journal Of Trauma And Emergency Surgery}, number = {5}, publisher = {Springer}, address = {Berlin}, issn = {1863-9941}, doi = {10.1007/s00068-016-0693-2}, pages = {537 -- 545}, year = {2016}, abstract = {Purpose The most commonly used mobility assessments for screening risk of falls among older adults are rating scales such as the Tinetti performance oriented mobility assessment (POMA). However, its correlation with falls is not always predictable and disadvantages of the scale include difficulty to assess many of the items on a 3-point scale and poor specificity. The purpose of this study was to describe the ability of the new Aachen Mobility and Balance Index (AMBI) to discriminate between subjects with a fall history and subjects without such events in comparison to the Tinetti POMA Scale. Methods For this prospective cohort study, 24 participants in the study group and 10 in the control group were selected from a population of patients in our hospital who had met the stringent inclusion criteria. Both groups completed the Tinetti POMA Scale (gait and balance component) and the AMBI (tandem stance, tandem walk, ten-meter-walk-test, sit-to-stand with five repetitions, 360° turns, timed-up-and-go-test and measurement of the dominant hand grip strength). A history of falls and hospitalization in the past year were evaluated retrospectively. The relationships among the mobility tests were examined with Bland-Altmananalysis. Receiver-operated characteristics curves, sensitivity and specificity were calculated. Results The study showed a strong negative correlation between the AMBI (17 points max., highest fall risk) and Tinetti POMA Scale (28 points max., lowest fall risk; r = -0.78, p < 0.001) with an excellent discrimination between community-dwelling older people and a younger control group. However, there were no differences in any of the mobility and balance measurements between participants with and without a fall history with equal characteristics in test comparison (AMBI vs. Tinetti POMA Scale: AUC 0.570 vs. 0.598; p = 0.762). The Tinetti POMA Scale (cut-off <20 points) showed a sensitivity of 0.45 and a specificity of 0.69, the AMBI a sensitivity of 0.64 and a specificity of 0.46 (cut-off >5 points). Conclusion The AMBI comprises mobility and balance tasks with increasing difficulty as well as a measurement of the dominant hand-grip strength. Its ability to identify fallers was comparable to the Tinetti POMA Scale. However, both measurement sets showed shortcomings in discrimination between fallers and non-fallers based on a self-reported retrospective falls-status.}, language = {en} } @article{DollWagnerWagneretal.2016, author = {Doll, Theodor and Wagner, Torsten and Wagner, Patrick and Sch{\"o}ning, Michael Josef}, title = {Engineering of functional interfaces / Theodor Doll ; Torsten Wagner ; Patrick Wagner ; Michael J. Sch{\"o}ning (eds.)}, series = {Physica status solidi (a)}, volume = {213}, journal = {Physica status solidi (a)}, number = {6}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1862-6319}, doi = {10.1002/pssa.201670641}, pages = {1393 -- 1394}, year = {2016}, language = {en} }