| 1. |
- Lundström, Ingemar, et al.
(author)
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Recent developments in field-effect gas sensors
- 1995
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In: Sensors and actuators. B, Chemical. - : Elsevier. - 0925-4005 .- 1873-3077. ; 23:2-3, s. 127-133
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Journal article (peer-reviewed)abstract
- Some of the ongoing studies at our laboratory of gas-sensitive field-effect devices with catalytic metal gates are reviewed. More particularly, we discuss the use of such devices in so-called electronic noses due to the possibility of changing the selectivity patterns of the devices by the choice of catalytic metal and operation temperature. Several examples of the application of electronic noses consisting of field-effect devices in combination with metal oxide-based sensors are given. Finally, a summary is given of some remaining scientific problems and studies related to the understanding and development of gas-sensitive field-effect devices.
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| 2. |
- Belov, Ilja, et al.
(author)
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CFD analysis of packaging and mounting solutions for SiC-based gas sensors in automotive applications
- 2006
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In: Sensor Letters. - 1546-198X. ; 4:1, s. 29-37
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Journal article (peer-reviewed)abstract
- Simulation-based guidelines were developed for designing tube-mounted gas sensors in the exhaust pipes of diesel and petrol engines, taking into account thermal constraints and gas flow conditions. Different block and tube mounting alternatives for SiC-based gas sensors were studied by means of temperature measurements and simulation of steady state heat transfer and gas flow. Design variables included the number of fins in the heat sink mounted on the inlet tube, the inlet construction, the mounting tube orientation, and the micro-heater substrate placement inside the mounting tube. The most preferable tube mounting design was determined with respect to the thermal performance of the sensor structure and with respect to the gas flow parameters, which are important for the sensor's selectivity, sensitivity and response time.
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| 3. |
- Belov, Ilja, et al.
(author)
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Thermal and flow analysis of SiC-based gas sensors for automotive applications
- 2004
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In: Proceedings of the 5th International Conference on Thermal and Mechanical Simulation and Experiments in Microelectronics and Microsystems, 2004. - : IEEE. - 0780384202 ; , s. 475-482
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Conference paper (peer-reviewed)abstract
- Different block and tube mounting alternatives for SiC-based gas sensors were studied by means of temperature measurements and simulation of heat transfer and gas flow for steady state conditions. The most preferable tube mounting design was determined. Simulation-based guidelines were developed for designing tube-mounted gas sensors in the exhaust pipes of diesel and petrol engines, taking into account thermal constraints and flow conditions.
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| 4. |
- Björkman, Hans, et al.
(author)
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Political entrepreneurship in action research : learning from two cases
- 2005
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In: Journal of Organizational Change Management. - : Emerald. - 1758-7816 .- 0953-4814. ; 18:5, s. 399-415
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Journal article (peer-reviewed)abstract
- Purpose To discuss political entrepreneurship as a capability to enable durable insider action research projects. Design/methodology/approach The two authors utilize auto‐ethnographic methods in order to evaluate and draw inferences from their own actions as insider action researchers. The paper draws on action research theory and theories on political entrepreneurship. Findings Political entrepreneurship is an important factor behind success or failure in action research projects, but has, despite this, been scarcely discussed in the action research literature. Findings indicate that a political entrepreneurship repertoire consisting of capabilities to find red‐hot issues for one's research, to use the inside of the organization in the research efforts, to use and diffuse the research results, and, finally, to work on the positioning of one's relational platform. Research limitations/implications The study is based upon case studies in two organizations. Its implications may be further developed through studies in a wider array of settings. Practical implications The study provides valuable knowledge for organizations intending to participate in (insider) action research as well as for (insider) action researchers. Originality/value Political entrepreneurship in action research is scarcely discussed in action research theory and hence the paper addresses an important research gap. Moreover, the presented implications have a certain practical value for organizations and researchers.
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| 5. |
- Briand, D., et al.
(author)
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Low-power micromachined MOSFET gas sensor
- 2000
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In: Journal of microelectromechanical systems. - : Institute of Electrical and Electronics Engineers (IEEE). - 1057-7157 .- 1941-0158. ; 9:3, s. 303-308
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Journal article (peer-reviewed)abstract
- This paper reports on the design, fabrication, and characterization of the first low-power consumption MOSFET gas sensor. The novel MOSFET array gas sensor has been fabricated using anisotropic bulk silicon micromachining. A heating resistor, a diode used as temperature sensor, and four MOSFETs are located in a silicon island suspended by a dielectric membrane. The membrane has a low thermal conductivity coefficient and, therefore, thermally isolates the electronic components from the chip frame. This low thermal mass device allows the reduction of the power consumption to a value of 90 mW for an array of four MOSFETs at an operating temperature of 170 °C. Three of the MOSFETs have their gate covered with thin catalytic metals and are used as gas sensors. The fourth one has a standard gate covered with nitride and could act as a reference. The sensor was tested under different gaseous atmospheres and has shown good gas sensitivities to hydrogen and ammonia. The low-power MOSFET array gas sensor presented is suitable for applications in portable gas sensor instruments, electronic noses, and automobiles.
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| 6. |
- Briand, D., et al.
(author)
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Modulated operating temperature for MOSFET gas sensors : Hydrogen recovery time reduction and gas discrimination
- 2003
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In: Sensors and actuators. B, Chemical. - 0925-4005 .- 1873-3077. ; 93:1-3, s. 276-285
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Conference paper (other academic/artistic)abstract
- This communication presents a modulated mode of operation for MOSFET gas sensors. A low-power micromachined device allows pulsing the temperature of MOSFET gas sensors with a time constant less than 100ms. Modulating the temperature during the gas exposure modifies the kinetics of the gas reactions with the sensing film. The way the sensor response is modified by the temperature modulation depends on the sensor "history", on the nature of the surrounding gaseous atmosphere, and on the type of materials used as catalytic sensing film. Pulsing the temperature up just after the gas exposure can reduce the recovery time for specific applications, such as for hydrogen detection. Cycling the temperature can allow the discrimination between different gas mixtures. Discrimination was shown for gaseous mixtures of hydrogen and ammonia in air. The results obtained indicate that a "smart" combination of sample and temperature profile could be used to expand the information content in the sensor response. © 2003 Elsevier Science B.V. All rights reserved.
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| 7. |
- Briand, D., et al.
(author)
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Thermally isolated MOSFET for gas sending application
- 2001
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In: IEEE Electron Device Letters. - : Institute of Electrical and Electronics Engineers (IEEE). - 0741-3106 .- 1558-0563. ; 22:1, s. 11-13
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Journal article (peer-reviewed)abstract
- This work reports on thermally isolated electronic components for gas sensing applications. The device is composed of an array of 4 MOSFET, a diode and a semiconductor resistor integrated on a micro-hotplate, which is fabricated using bulk micromachining of silicon. The thermal efficiency of the device is 2°C/mW with a thermal constant less than 100 ms. Holes are made in the passivation film over the gates of the MOSFET and gas sensitive films deposited on top of the gate insulator. The low thermal mass device realized allows new modes of operation for MOSFET gas sensors such as a combination of the field and thermal effects and a pulsed temperature mode of operation.
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| 8. |
- Eriksson, Mats, 1963-, et al.
(author)
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Drinking water monitoring with voltammetric sensors
- 2011
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In: Procedia Engineering. - : Elsevier. - 1877-7058. ; 25, s. 1165-1168
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Journal article (peer-reviewed)abstract
- Pulsed voltammetry has been applied to drinking water monitoring. This non-selective technique facilitates detection of several different threats to the drinking water. A multivariate algorithm shows that anomaly detection is possible with a minimum of false alarms. Multivariate analysis can also be used to classify different types of substances added to the drinking water. Low concentrations of sewage water contaminating the drinking water can be detected. A network of such sensors is envisaged to facilitate real-time and on-line monitoring of drinking water distribution networks.
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| 9. |
- Eriksson, Mats, et al.
(author)
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Event Detection in Crisis Management Systems
- 2009
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In: Procedia Chemistry. - : Elsevier. - 1876-6196. ; 1:1, s. 1055-1058
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Journal article (peer-reviewed)abstract
- The EVENT project concerns drinking water surveillance and includes sensors and algorithms that detect anomalies in the drinking water properties, communication of the evaluated sensor data to a crises management system and presentation of information that is relevant for the end users of the crises management system. We have chosen to focus on a sensor technique based on an "electronic tongue", since this robust type of non-selective sensor, can detect a plurality of anomalies without the need of a specific sensor for each type of event. Measurements of natural variations and contamination events are presented and discussed.
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| 10. |
- Harfeldt, Kristin, et al.
(author)
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Spectroscopic differences in posterior insula in patients with chronic temporomandibular pain
- 2018
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In: Scandinavian Journal of Pain. - : De Gruyter Open. - 1877-8860 .- 1877-8879. ; 18:3, s. 351-361
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Journal article (peer-reviewed)abstract
- Background and aims: Chronic pain including temporomandibular disorder (TMD) pain involves a complex interplay between peripheral and central sensitization, endogenous modulatory pathways, cortical processing and integration and numerous psychological, behavioral and social factors. The aim of this study was to compare spectroscopic patterns of N-Acetyl-aspartate (NAA), total creatine (tCr), choline (Cho), myo-inositol (MI), glutamate (Glu), and the combination of Glu and glutamine in the posterior insula in patients with chronic generalized or regional chronic TMD pain (gTMD and rTMD, respectively) compared to healthy individuals (HI) in relation to clinical findings of TMD pain. Methods: Thirty-six female patients with chronic rTMD or gTMD with at least 3 months duration were included in the study. Ten healthy women were included as controls. All participants completed a questionnaire that comprised assessment of degrees of depression, anxiety, stress, catastrophizing, pain intensity, disability and locations. A clinical Diagnostic Criteria for Temporomandibular Disorders examination that comprised assessment of pain locations, headache, mouth opening capacity, pain on mandibular movement, pain on palpation and temporomandibular joint noises was performed. Pressure-pain threshold (PPT) over the masseter muscle and temporal summation to pressure stimuli were assessed with an algometer. Within a week all participants underwent non-contrast enhanced MRI on a 3T MR scanner assessing T1-w and T2-w fluid attenuation inversion recovery. A single-voxel H-1-MRS examination using point-resolved spectroscopy was performed. The metabolite concentrations of NAA, tCr, Cho, MI, Glu and Glx were analyzed with the LC model. Metabolite levels were calculated as absolute concentrations, normalized to the water signal. Metabolite concentrations were used for statistical analysis from the LC model if the Cramer-Rao bounds were less than 20%. In addition, the ratios NAA/tCr, Cho/tCr, Glu/tCr and MI/tCr were calculated. Results: The results showed significantly higher tCr levels within the posterior insula in patients with rTMD or gTMD pain than in HI (p = 0.029). Cho was negatively correlated to maximum mouth opening capacity with or without pain (r(s) = -0.42, n = 28, p = 0.031 and r(s) = -0.48, n = 28, p = 0.034, respectively) as well as pressure-pain threshold on the hand (r(s) = -0.41, n = 28, p = 0.031). Glu was positively correlated to temporal summation to painful mechanical stimuli (r(s) = 0.42, n = 26, p = 0.034). Conclusions: The present study found that increased concentrations of Cho and Glu in the posterior insular cortex is related to clinical characteristics of chronic TMD pain, including generalized pain. These findings provide new evidence about the critical involvement of the posterior insular cortex and the neurobiology underlying TMD pain in both regional and generalized manifestations. Implications: The findings in this study have indirect implications for the diagnosis and management of TMD patients. That said, the findings provide new evidence about the critical involvement of the posterior insular cortex and the neurobiology underlying TMD pain in both regional and generalized manifestations. It is also a further step towards understanding and accepting chronic pain as a disorder in itself.
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