Refine
Year of publication
- 2024 (22)
- 2023 (38)
- 2022 (51)
- 2021 (56)
- 2020 (59)
- 2019 (70)
- 2018 (68)
- 2017 (67)
- 2016 (54)
- 2015 (70)
- 2014 (65)
- 2013 (65)
- 2012 (72)
- 2011 (82)
- 2010 (72)
- 2009 (85)
- 2008 (61)
- 2007 (57)
- 2006 (75)
- 2005 (48)
- 2004 (85)
- 2003 (57)
- 2002 (55)
- 2001 (54)
- 2000 (65)
- 1999 (40)
- 1998 (39)
- 1997 (36)
- 1996 (32)
- 1995 (19)
- 1994 (13)
- 1993 (19)
- 1992 (13)
- 1991 (12)
- 1990 (17)
- 1989 (21)
- 1988 (22)
- 1987 (26)
- 1986 (7)
- 1985 (10)
- 1984 (9)
- 1983 (6)
- 1982 (24)
- 1981 (16)
- 1980 (30)
- 1979 (20)
- 1978 (27)
- 1977 (13)
- 1976 (16)
- 1975 (14)
- 1974 (4)
- 1973 (3)
- 1972 (6)
- 1971 (1)
- 1969 (1)
- 1968 (2)
- 1967 (1)
Institute
- Fachbereich Medizintechnik und Technomathematik (2072) (remove)
Document Type
- Article (1591)
- Conference Proceeding (241)
- Book (96)
- Part of a Book (62)
- Doctoral Thesis (27)
- Patent (17)
- Report (15)
- Other (9)
- Habilitation (4)
- Lecture (3)
Keywords
- Biosensor (25)
- Finite-Elemente-Methode (16)
- CAD (15)
- civil engineering (14)
- Bauingenieurwesen (13)
- Einspielen <Werkstoff> (13)
- shakedown analysis (9)
- FEM (6)
- Limit analysis (6)
- Shakedown analysis (6)
Optical coherence tomography : a potential tool to predict premature rupture of fetal membranes
(2013)
Air-pulse corneal applanation signal curve parameters for the characterisation of keratoconus
(2011)
Quartz crystal nanobalance (QCN) sensors are considered as powerful masssensitive sensors to determine materials in the sub-nanogram level. In this study, a single piezoelectric quartz crystal nanobalance modified with polystyrene was employed to detect benzene, toluene, ethylbenzene and xylene (BTEX compounds). The frequency shift of the QCN sensor was found to be linear against the BTEX compound concentrations in the range about 1-45 mg l-1. The correlation coefficients for benzene, toluene, ethylbenzene, and xylene were 0.991, 0.9977, 0.9946 and 0.9971, respectively. The principal component analysis was also utilized to process the frequency response data of the single piezoelectric crystal at different times, considering to the different adsorption-desorption dynamics of BTEX compounds. Using principal component analysis, it was found that over 90% of the data variance could still be explained by use of two principal components (PC1 and PC2). Subsequently, the successful identification of benzene and toluene was possible through the principal component analysis of the transient responses of the polystyrene modified QCN sensor. The results showed that the polystyrene-modified QCN had favorable identification and quantification performances for the BTEX compounds.
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 chemical imaging sensor is a chemical sensor which is capable of visualizing the spatial distribution of chemical species in sample solution. In this study, a novel measurement system based on the chemical imaging sensor was developed to observe the inside of a Y-shaped microfluidic channel while injecting two sample solutions from two branches. From the collected chemical images, it was clearly observed that the injected solutions formed laminar flows in the microfluidic channel. In addition, ion diffusion across the laminar flows was observed. This label-free method can acquire quantitative data of ion distribution and diffusion in microfluidic devices, which can be used to determine the diffusion coefficients, and therefore, the molecular weights of chemical species in the sample solution.
The chemical imaging sensor, which is based on the principle of the light-addressable potentiometric sensor (LAPS), is a powerful tool to visualize the spatial distribution of chemical species on the sensor surface. The spatial resolution of this sensor depends on the diffusion of photocarriers excited by a modulated light. In this study, a novel hybrid fiber-optic illumination was developed to enhance the spatial resolution. It consists of a modulated light probe to generate a photocurrent signal and a ring of constant light, which suppresses the lateral diffusion of minority carriers excited by the modulated light. It is demonstrated that the spatial resolution was improved from 92 μm to 68 μm.
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) inthe sample. In this study, a novel wound-healing assay is proposed, in which the chemical imaging sensor operated in SPIM mode is applied to monitor the defect of a cell layer brought into proximity of the sensing surface.A reduced impedance inside the defect, which was artificially formed ina cell layer, was successfully visualized in a photocurrent image.
A high-Q resonance-mode measurement of EIS capacitive sensor by elimination of series resistance
(2017)
An EIS capacitive sensor is a semiconductor-based potentiometric sensor, which is sensitive to the ion concentration or pH value of the solution in contact with the sensing surface. To detect a small change in the ion concentration or pH, a small capacitance change must be detected. Recently, a resonance-mode measurement was proposed, in which an inductor was connected to the EIS capacitive sensor and the resonant frequency was correlated with the pH value. In this study, the Q factor of the resonant circuit was enhanced by canceling the internal resistance of the reference electrode and the internal resistance of the inductor coil with the help of a bypass capacitor and a negative impedance converter, respectively. 1% variation of the signal in the developed system corresponded to a pH change of 3.93 mpH, which was about 1/12 of the conventional method, suggesting a better performance in detection of a small pH change.