Elsevier
Refine
Year of publication
Institute
- Fachbereich Medizintechnik und Technomathematik (183)
- INB - Institut für Nano- und Biotechnologien (105)
- IfB - Institut für Bioengineering (65)
- Fachbereich Chemie und Biotechnologie (57)
- Fachbereich Luft- und Raumfahrttechnik (35)
- Fachbereich Energietechnik (29)
- Fachbereich Maschinenbau und Mechatronik (16)
- Fachbereich Bauingenieurwesen (14)
- Solar-Institut Jülich (14)
- Fachbereich Elektrotechnik und Informationstechnik (9)
Has Fulltext
- no (350) (remove)
Document Type
- Article (328)
- Part of a Book (12)
- Conference Proceeding (9)
- Other (1)
Keywords
- Earthquake (4)
- LAPS (4)
- Gamification (3)
- Heparin (3)
- Central receiver power plant (2)
- Central receiver system (2)
- Chemometrics (2)
- Concentrated solar collector (2)
- Concentrated systems (2)
- Field-effect sensor (2)
- Gas turbine (2)
- IR spectroscopy (2)
- Light-addressable potentiometric sensor (2)
- NMR spectroscopy (2)
- Solar concentration (2)
- Standardization (2)
- hydrogen peroxide (2)
- (Bio)degradation (1)
- Active humidity control (1)
- Adaptive Systems (1)
- Adaptive control (1)
- Additive Manufacturing (1)
- Additive manufacturing (1)
- Alginate beads (1)
- Alzheimer's disease (1)
- Anastomotic leakage (1)
- Assembly (1)
- Assistive technology (1)
- Asymptotic efficiency (1)
- Augmented Reality (1)
- Authenticity (1)
- Autolysis (1)
- Automatic control (1)
- Avalanche (1)
- Bacillus atrophaeus (1)
- Binder Jetting (1)
- Biocomposites (1)
- Biomass (1)
- Bootstrapping (1)
- Borehole heat exchanger (1)
- CNOT (1)
- Calorimetric gas sensor (1)
- Capacitive field-effect (1)
- Cardiac tissue (1)
- Cell permeability (1)
- CellDrum (1)
- Cellular force (1)
- Censored data (1)
- Chemical images (1)
- Chemical imaging sensor (1)
- Chemical sensor (1)
- Chimeric liver-humanized mice (1)
- Coal (1)
- Collective risk model (1)
- Competitiveness (1)
- Computational biomechanics (1)
- Concentrating solar power (1)
- Constitutive model (1)
- Contractile tension (1)
- Cross border adjustment mechanism (1)
- Crude heparin (1)
- C–V method (1)
- DLR-ESTEC GOSSAMER roadmap for solar sailing (1)
- DNA biosensor (1)
- DNA hybridization (1)
- Damage mechanics theory (1)
- Decomposition (1)
- Decoupling (1)
- Dehydrogenase (1)
- Detergent protease (1)
- Deuterated solvents (1)
- Deuterium NMR (1)
- Diaphorase (1)
- Digital Twin (1)
- Dimensional splitting (1)
- Directed Energy Deposition (1)
- Discontinuous fractures (1)
- Drinfeld modules (1)
- Drug distribution (1)
- Drug metabolism (1)
- Drug simulation (1)
- Dry-low-NOx (DLN) combustion (1)
- Dynamic simulation (1)
- E-Mobility (1)
- EGG (1)
- EIS capacitive sensor (1)
- Electrochemical impedance spectroscopy (1)
- Electrolyte–insulator–semiconductor (1)
- Electromechanical modeling (1)
- End-to-end colorectal anastomosis (1)
- Endothelial cells (1)
- Energy-intensive industry (1)
- Enzymatic biosensor (1)
- Enzyme logic gate (1)
- Error Recovery (1)
- Exponential time differencing (1)
- External knee adduction moments (1)
- Extracellular enzymes (1)
- Fault detection (1)
- Field effect (1)
- Finite differences (1)
- Finite element analysis (1)
- Finite element modelling (1)
- Floor prices (1)
- Fracture classification (1)
- Frame structure (1)
- Freeze–thaw process (1)
- Frequency adaption (1)
- Fresnel collector (1)
- Fresnel power plant (1)
- Fuel cell (1)
- GOSSAMER-1 (1)
- Gamma distribution (1)
- Goodness-of-fit test (1)
- H2 (1)
- Hazard assessment (1)
- Health management system (1)
- Heat transport (1)
- High hydrogen combustion (1)
- Higher derivations (1)
- Hodgkin–Huxley models (1)
- Homogenization (1)
- Human-Computer interaction (1)
- Humidity (1)
- Hybridization (1)
- Hydrogen combustion (1)
- Hydrogen gas turbine (1)
- Hydrogen peroxide (1)
- Hydrogenotrophic methanogens (1)
- Hypersecretion (1)
- INSYSME (1)
- Imaging (1)
- Impedance analysis (1)
- Impedance spectroscopy (1)
- In-plane performance, isolation (1)
- Independence test (1)
- Infill wall design (1)
- Inorganic ions (1)
- Interplanetary flight (1)
- Interstellar objects (1)
- Inverse dynamic problem (1)
- Inverse kinematic problem (1)
- Ions (1)
- Iterative learning control (1)
- Knockout mice (1)
- L-PBF (1)
- LPBF (1)
- Label-free detection (1)
- Landslide tsunamis (1)
- Large scale tests (1)
- Larynx position (1)
- Laser-Powder Bed Fusion (1)
- Layer-by-layer adsorption (1)
- Level system (1)
- Light-addressable Potentiometric Sensor (1)
- Lipopolysaccharide (1)
- Liver (1)
- Low-field NMR (1)
- Manipulated variables (1)
- Marker-free mutagenesis (1)
- Masonry infill (1)
- Masonry partition walls (1)
- Matrix exponential (1)
- Methane (1)
- Methanogenesis (1)
- Micromix combustion (1)
- Mild cognitive impairment (1)
- Missions (1)
- Mobility transition (1)
- Molecular modelling (1)
- Molecular weight determination (1)
- Molten salt receiver system (1)
- Molten salt solar tower (1)
- Morphing (1)
- Multi-criteria decision analysis (1)
- Multi-storey (1)
- Musculoskeletal model (1)
- NMR (1)
- NMR exchange relaxometry (1)
- Natural fibres (1)
- Negative impedance convertor (1)
- Niacin (1)
- Non-model-based Evaluation (1)
- Non-parallel fissures (1)
- Numerical modelling (1)
- Online diagnostic (1)
- Optical and thermal analysis (1)
- Organic light-emitting diode display (1)
- Out-of-plane capacity (1)
- Overland flow (1)
- PEM fuel cell (1)
- PLS-regression (1)
- Parametric bootstrap (1)
- Periods (1)
- Piping (1)
- Poly(allylamine hydrochloride) (1)
- Poly(d,l-lacticacid) (1)
- Polyimide (1)
- Polymer-matrix composites (1)
- Powder Material (1)
- Power conversion systems (1)
- Preference assessment (1)
- Principal component analysis (1)
- Probability distribution mapping (1)
- Product-integration (1)
- Proper Orthogonal Decomposition (1)
- Pulsations (1)
- Q-criterion (1)
- Quality control (1)
- Quantum chemistry (1)
- Reaction-diffusion systems (1)
- Real distinct pole (1)
- Real-time monitoring (1)
- Recombinant activated protein C (1)
- Regionalization (1)
- Rehabilitation engineering (1)
- Reinforced concrete frame (1)
- Relative air humidity (1)
- Resonance-mode measurement (1)
- Retinal vessel analysis (1)
- Riboflavin (1)
- Robotic rehabilitation (1)
- Seismic loading (1)
- Semi-parametric random censorship model (1)
- Shoulder (1)
- Simultaneous determination (1)
- Slab deflection (1)
- Small spacecraft (1)
- Snow (1)
- Soft independent modeling of class analogy (1)
- Solar dish (1)
- Solar sail (1)
- Solitary waves (1)
- Spacecraft (1)
- Spleen (1)
- Steel industry (1)
- Stenotrophomonas maltophilia (1)
- Sterilisation process (1)
- Stress concentrations (1)
- Support System (1)
- Surgical staplers (1)
- Survival analysis (1)
- Tank (1)
- Thiamine (1)
- Tomography (1)
- Toxicology (1)
- Trajectories (1)
- Transcendence (1)
- Transfer impedance (1)
- Transient flux distribution (1)
- Two-phase modelling (1)
- USP (1)
- Uniaxial compression test (1)
- Uracil-phosphoribosyltransferase (1)
- User study (1)
- Vapnik–Čhervonenkis class (1)
- Variable height stapler design (1)
- Vasomotions (1)
- Virtual reality (1)
- Vitamin A (1)
- Vitamin B (1)
- Voice assessment (1)
- Volterra integral equation (1)
- XOR (1)
- anaesthetic complications (1)
- barium strontium titanate (1)
- calorimetric gas sensor (1)
- coherent structures (1)
- constructive alignment (1)
- contactless conductivity sensor (1)
- dental trauma (1)
- difficult airway (1)
- double-lumen tube intubation (1)
- enzymatic (bio)degradation (1)
- examination (1)
- field-effect sensor (1)
- hiPS cardiomyocytes (1)
- high-k material (1)
- hydraulic modelling (1)
- impedance spectroscopy (1)
- in-situ monitoring (1)
- intraclass correlation coefficient (1)
- lable-free detection (1)
- long-term retention (1)
- magnetic actuation (1)
- magnetic separation (1)
- magnetic tweezers (1)
- magnetophoretic velocity (1)
- model performance (1)
- multi-functional material (1)
- multimodal (1)
- novel photoexcitation method (1)
- poly(d, l-lactic acid) (1)
- practical learning (1)
- qNMR (1)
- shoulder (1)
- spatial resolution (1)
- standard error of measurement (1)
- sterilisation (1)
- stretch reflex (1)
- superparamagnetic bead (1)
- t-modules (1)
- test-retest reliability (1)
- tilted constant illumination (1)
- videolaryngoscopy (1)
Background and Objective
Effective leg extension training at a leg press requires high forces, which need to be controlled to avoid training-induced damage. In order to avoid high external knee adduction moments, which are one reason for unphysiological loadings on knee joint structures, both training movements and the whole reaction force vector need to be observed. In this study, the applicability of lateral and medial changes in foot orientation and position as possible manipulated variables to control external knee adduction moments is investigated. As secondary parameters both the medio-lateral position of the center of pressure and the frontal-plane orientation of the reaction force vector are analyzed.
Methods
Knee adduction moments are estimated using a dynamic model of the musculoskeletal system together with the measured reaction force vector and the motion of the subject by solving the inverse kinematic and dynamic problem. Six different foot conditions with varying positions and orientations of the foot in a static leg press are evaluated and compared to a neutral foot position.
Results
Both lateral and medial wedges under the foot and medial and lateral shifts of the foot can influence external knee adduction moments in the presented study with six healthy subjects. Different effects are observed with the varying conditions: the pose of the leg is changed and the direction and center of pressure of the reaction force vector is influenced. Each effect results in a different direction or center of pressure of the reaction force vector.
Conclusions
The results allow the conclusion that foot position and orientation can be used as manipulated variables in a control loop to actively control knee adduction moments in leg extension training.
We prove characterizations of the existence of perfect ƒ-matchings in uniform mengerian and perfect hypergraphs. Moreover, we investigate the ƒ-factor problem in balanced hypergraphs. For uniform balanced hypergraphs we prove two existence theorems with purely combinatorial arguments, whereas for non-uniform balanced hypergraphs we show that the ƒ-factor problem is NP-hard.
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.
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.
Sensitivity of turbulent Schmidt number and turbulence model to simulations of jets in crossflow
(2016)
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.
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.
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.
The light-addressable potentiometric sensor (LAPS) has the unique feature to address different regions of a sensor surface without the need of complex structures. Measurements at different locations on the sensor surface can be performed in a common analyte solution, which distinctly simplifies the fluidic set-up. However, the measurement in a single analyte chamber prevents the application of different drugs or different concentrations of a drug to each measurement spot at the same time as in the case of multi-reservoir-based set-ups. In this work, the authors designed a LAPS-based set-up for cell culture screening that utilises magnetic beads loaded with the endotoxin (lipopolysaccharides, LPS), to generate a spatially distributed gradient of analyte concentration. Different external magnetic fields can be adjusted to move the magnetic beads loaded with a specific drug within the measurement cell. By recording the metabolic activities of a cell layer cultured on top of the LAPS surface, this work shows the possibility to apply different concentrations of a sample along the LAPS measurement spots within a common analyte solution.
The msprop program presented in this work is capable of solving the Maxwell–Schrödinger equations for one or several laser fields propagating through a medium of quantum optical few-level systems in one spatial dimension and in time. In particular, it allows to numerically treat systems in which a laser field interacts with the medium with both its electric and magnetic component at the same time. The internal dynamics of the few-level system is modeled by a quantum optical master equation which includes coherent processes due to optical transitions driven by the laser fields as well as incoherent processes due to decay and dephasing. The propagation dynamics of the laser fields is treated in slowly varying envelope approximation resulting in a first order wave equation for each laser field envelope function. The program employs an Adams predictor formula second order in time to integrate the quantum optical master equation and a Lax–Wendroff scheme second order in space and time to evolve the wave equations for the fields. The source function in the Lax–Wendroff scheme is specifically adapted to allow taking into account the simultaneous coupling of a laser field to the polarization and the magnetization of the medium. To reduce execution time, a customized data structure is implemented and explained. In three examples the features of the program are demonstrated and the treatment of a system with a phase-dependent cross coupling of the electric and magnetic field component of a laser field is shown.
Visualization of the recovery process of defects in a cultured cell layer by chemical imaging sensor
(2016)
The chemical imaging sensor is a field-effect sensor which is able to visualize both the distribution of ions (in LAPS mode) and the distribution of impedance (in SPIM mode) in the sample. In this study, a novel cell assay is proposed, in which the chemical imaging sensor operated in SPIM mode is applied to monitor the recovery of defects in a cell layer brought into proximity of the sensing surface. A reduced impedance at a defect formed artificially in a cell layer was successfully visualized in a photocurrent image. The cell layer was cultured over two weeks, during which the temporal change of the photocurrent distribution corresponding to the recovery of the defect was observed.
A comparative performance analysis of the CFD platforms OpenFOAM and FLOW-3D is presented, focusing on a 3D swirling turbulent flow: a steady hydraulic jump at low Reynolds number. Turbulence is treated using RANS approach RNG k-ε. A Volume Of Fluid (VOF) method is used to track the air–water interface, consequently aeration is modeled using an Eulerian–Eulerian approach. Structured meshes of cubic elements are used to discretize the channel geometry. The numerical model accuracy is assessed comparing representative hydraulic jump variables (sequent depth ratio, roller length, mean velocity profiles, velocity decay or free surface profile) to experimental data. The model results are also compared to previous studies to broaden the result validation. Both codes reproduced the phenomenon under study concurring with experimental data, although special care must be taken when swirling flows occur. Both models can be used to reproduce the hydraulic performance of energy dissipation structures at low Reynolds numbers.
A multi-spot light-addressable potentiometric sensor (LAPS), which belongs to the family of semiconductor field-effect devices, was applied for label-free detection of double-stranded deoxyribonucleic acid (dsDNA) molecules by their intrinsic molecular charge. To reduce the distance between the DNA charge and sensor surface and thus, to enhance the electrostatic coupling between the dsDNA molecules and the LAPS, the negatively charged dsDNA molecules were electrostatically adsorbed onto the gate surface of the LAPS covered with a positively charged weak polyelectrolyte layer of PAH (poly(allylamine hydrochloride)). The surface potential changes in each spot of the LAPS, induced by the layer-by-layer adsorption of a PAH/dsDNA bilayer, were recorded by means of photocurrent-voltage and constant-photocurrent measurements. In addition, the surface morphology of the gate surface before and after consecutive electrostatic adsorption of PAH and dsDNA layers was studied by atomic force microscopy measurements. Moreover, fluorescence microscopy was used to verify the successful adsorption of dsDNA molecules onto the PAH-modified LAPS surface. A high sensor signal of 25 mV was registered after adsorption of 10 nM dsDNA molecules. The lower detection limit is down to 0.1 nM dsDNA. The obtained results demonstrate that the PAH-modified LAPS device provides a convenient and rapid platform for the direct label-free electrical detection of in-solution hybridized dsDNA molecules.
Based on an identifying Volterra type integral equation for randomly right censored observations from a lifetime distribution function F, we solve the corresponding estimating equation by an explicit and implicit Euler scheme. While the first approach results in some known estimators, the second one produces new semi-parametric and pre-smoothed Kaplan–Meier estimators which are real distribution functions rather than sub-distribution functions as the former ones are. This property of the new estimators is particular useful if one wants to estimate the expected lifetime restricted to the support of the observation time.
Specifically, we focus on estimation under the semi-parametric random censorship model (SRCM), that is, a random censorship model where the conditional expectation of the censoring indicator given the observation belongs to a parametric family. We show that some estimated linear functionals which are based on the new semi-parametric estimator are strong consistent, asymptotically normal, and efficient under SRCM. In a small simulation study, the performance of the new estimator is illustrated under moderate sample sizes. Finally, we apply the new estimator to a well-known real dataset.
We present an electromechanically coupled computational model for the investigation of a thin cardiac tissue construct consisting of human-induced pluripotent stem cell-derived atrial, ventricular and sinoatrial cardiomyocytes. The mechanical and electrophysiological parts of the finite element model, as well as their coupling are explained in detail. The model is implemented in the open source finite element code Code_Aster and is employed for the simulation of a thin circular membrane deflected by a monolayer of autonomously beating, circular, thin cardiac tissue. Two cardio-active drugs, S-Bay K8644 and veratridine, are applied in experiments and simulations and are investigated with respect to their chronotropic effects on the tissue. These results demonstrate the potential of coupled micro- and macroscopic electromechanical models of cardiac tissue to be adapted to experimental results at the cellular level. Further model improvements are discussed taking into account experimentally measurable quantities that can easily be extracted from the obtained experimental results. The goal is to estimate the potential to adapt the presented model to sample specific cell cultures.
Operational Modal Analysis (OMA) is a promising candidate for flutter testing and Structural Health Monitoring (SHM) of aircraft wings that are passively excited by wind loads. However, no studies have been published where OMA is tested in transonic flows, which is the dominant condition for large civil aircraft and is characterized by complex and unique aerodynamic phenomena. We use data from the HIRENASD large-scale wind tunnel experiment to automatically extract modal parameters from an ambiently excited wing operated in the transonic regime using two OMA methods: Stochastic Subspace Identification (SSI) and Frequency Domain Decomposition (FDD). The system response is evaluated based on accelerometer measurements. The excitation is investigated from surface pressure measurements. The forcing function is shown to be non-white, non-stationary and contaminated by narrow-banded transonic disturbances. All these properties violate fundamental OMA assumptions about the forcing function. Despite this, all physical modes in the investigated frequency range were successfully identified, and in addition transonic pressure waves were identified as physical modes as well. The SSI method showed superior identification capabilities for the investigated case. The investigation shows that complex transonic flows can interfere with OMA. This can make existing approaches for modal tracking unsuitable for their application to aircraft wings operated in the transonic flight regime. Approaches to separate the true physical modes from the transonic disturbances are discussed.
In this study, we show that synthetic sapphire (Al₂O₃), an established implant material, can also serve as a platform material for biosensors comparable to nanocrystalline diamond. Sapphire chips, beads, and powder were first modified with (3-aminopropyl) triethoxysilane (APTES), followed by succinic anhydride (SA), and finally single-stranded probe DNA was EDC coupled to the functionalized layer. The presence of the APTES-SA layer on sapphire powders was confirmed by thermogravimetric analyis and Fourier-transform infrared spectroscopy. Using planar sapphire chips as substrates and X-ray photoelectron spectroscopy (XPS) as surface-sensitive tool, the sequence of individual layers was analyzed with respect to their chemical state, enabling the quantification of areal densities of the involved molecular units. Fluorescence microscopy was used to demonstrate the hybridization of fluorescently tagged target DNA to the probe DNA, including denaturation- and re-hybridization experiments. Due to its high thermal conductivity, synthetic sapphire is especially suitable as a chip material for the heat-transfer method, which was employed to distinguish complementary- and non-complementary DNA duplexes containing single-nucleotide polymorphisms. These results indicate that it is possible to detect mutations electronically with a chemically resilient and electrically insulating chip material.
The sterilization of packages in aseptic food processes is highly significant to maintain a consumer-safe product with extended shelf-life. Today, the sterilization of food packages is predominantly accomplished by gaseous hydrogen peroxide (H2O2) in combination with heat. In order to monitor this sterilization process, calorimetric gas sensors as differential set-up of two platinum temperature sensors representing a catalytically active (additionally deposition of MnO2) and a passive segment have been recently developed. The temperature rise of the exothermic decomposition serves as an indicator of the present H2O2 concentration. In the present work, a theoretical approach considering the sensor’s thermochemistry and physical transport phenomena was formulated to evaluate the temperature rise based on the energy content of gaseous H2O2. In a further part of this work, three polymers have been analyzed with respect to their application as passivation materials. The examined polymers are photoresist SU-8, perfluoroalkoxy (PFA) and fluorinated ethylene propylene (FEP). Thermal analyses by means of differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) have been conducted to determine the operation limits of the polymers. The overall chemical resistance and stability of the polymers against the harsh environmental conditions during the sterilization process have been examined by attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR).
The chemical imaging sensor was applied to in-situ pH imaging of the solution in the vicinity of a corroding surface of stainless steel under potentiostatic polarization. A test piece of polished stainless steel was placed on the sensing surface leaving a narrow gap filled with artificial seawater and the stainless steel was corroded under polarization. The pH images obtained during polarization showed correspondence between the region of lower pH and the site of corrosion. It was also found that the pH value in the gap became as low as 2 by polarization, which triggered corrosion.
The Saturnian moon Enceladus with its extensive water bodies underneath a thick ice sheet cover is a potential candidate for extraterrestrial life. Direct exploration of such extraterrestrial aquatic ecosystems requires advanced access and sampling technologies with a high level of autonomy. A new technological approach has been developed as part of the collaborative research project Enceladus Explorer (EnEx). The concept is based upon a minimally invasive melting probe called the IceMole. The force-regulated, heater-controlled IceMole is able to travel along a curved trajectory as well as upwards. Hence, it allows maneuvers which may be necessary for obstacle avoidance or target selection. Maneuverability, however, necessitates a sophisticated on-board navigation system capable of autonomous operations. The development of such a navigational system has been the focal part of the EnEx project. The original IceMole has been further developed to include relative positioning based on in-ice attitude determination, acoustic positioning, ultrasonic obstacle and target detection integrated through a high-level sensor fusion. This paper describes the EnEx technology and discusses implications for an actual extraterrestrial mission concept.