| 1. |
|
|
| 2. |
|
|
| 3. |
|
|
| 4. |
- Lloyd-Spets, Anita, et al.
(författare)
-
MISiCFET chemical gas sensors for high temperature and corrosive environment applications
- 2002
-
Ingår i: Materials Science Forum. - 0255-5476 .- 1662-9752. ; 389-3, s. 1415-1418
-
Tidskriftsartikel (refereegranskat)abstract
- A chemical gas sensor based on a silicon carbide field effect transistor with a catalytic gate metal has been under development for a number of years. The buried gate design allows the sensor to operate at high temperatures, routinely up to 600degreesC and for at least three days at 700degreesC. The chemical inertness of silicon carbide makes it a suitable sensor technology for applications in corrosive environments such as exhaust gases and flue gases from boilers. The selectivity of the sensor devices is established through the choice of type and structure of the gate metal as well as the operation temperature. In this way NH3 sensors with low cross sensitivity to NOx have been demonstrated as potential sensors for control of selective catalytic reduction (SCR) of NOx by urea injection into diesel exhausts. The hardness of the silicon carbide makes it for example more resistant to water splash at cold start of a petrol engine than existing technologies, and a sensor which can control the air to fuel ratio, before the exhaust gases are heated, has been demonstrated. Silicon carbide sensors are also tested in flue gases from boilers. Efficient regulation of the combustion in a boiler will decrease fuel consumption and reduce emissions.
|
|
| 5. |
- Lloyd-Spets, Anita, et al.
(författare)
-
SiC based field effect gas sensors for industrial applications
- 2001
-
Ingår i: Physica status solidi. A, Applied research. - 0031-8965 .- 1521-396X. ; 185:1, s. 15-25
-
Tidskriftsartikel (refereegranskat)abstract
- The development and field-testing of high-temperature sensors based on silicon carbide devices have shown promising results in several application areas. Silicon carbide based field-effect sensors can be operated over a large temperature range, 100-600 degreesC, and since silicon carbide is a chemically very inert material these sensors can be used in environments like exhaust gases and flue gases from boilers. The sensors respond to reducing gases like hydrogen, hydrocarbons and carbon monoxide. The use of different temperatures, different catalytic metals and different structures of the gate metal gives selectivity to different gases and arrays of sensors can be used to identify and monitor several components in gas mixtures. MOSFET sensors based on SIC combine the advantage of simple circuitry with a thicker insulator, which increases the long term stability of the devices. In this paper we describe silicon carbide MOSFET sensors and their performance and give: examples of industrial applications such as monitoring of car exhausts and flue gases. Chemometric methods have been used for the evaluation of the data.
|
|
| 6. |
|
|
| 7. |
- Lloyd-Donald, P, et al.
(författare)
-
Comparison of Thromboelastography and Conventional Coagulation Tests in Patients With Severe Liver Disease
- 2020
-
Ingår i: Clinical and applied thrombosis/hemostasis : official journal of the International Academy of Clinical and Applied Thrombosis/Hemostasis. - : SAGE Publications. - 1938-2723. ; 26, s. 1076029620925915-
-
Tidskriftsartikel (refereegranskat)abstract
- Thromboelastography (TEG) may provide rapid and clinically important coagulation information in acutely ill patients with chronic liver disease (CLD). Our objective was to describe the relationship between TEG and conventional coagulation tests (CCTs), which has not been previously explored in this population. Methods: In acutely ill patients with severe CLD (Child-Pugh score > 9, category C), we conducted a prospective observational study investigating coagulation assessment as measured by both CCTs and TEG. We used quantile regression to explore 30 associations between TEG parameters and corresponding CCTs. We compared TEG and CCT measures of coagulation initiation, clot formation, clot strength, and fibrinolysis. Results: We studied 34 patients on a total of 109 occasions. We observed inconsistent associations between TEG and CCT measures of coagulation initiation: TEG (citrated kaolin [CK] assay) standard reaction time and international normalized ratio: R 2 = 0.117 ( P = .044). Conversely, there were strong and consistent associations between tests of clot formation: TEG (CK) kinetics time and fibrinogen: R 2 = 0.202 ( P < .0001) and TEG (CK) α angle and fibrinogen 0.263 ( P < .0001). We also observed strong associations between tests of clot strength, specifically TEG MA and conventional fibrinogen levels, across all TEG assays: MA (CK) and fibrinogen: R 2 = 0.485 ( P < .0001). There were no associations between TEG and D-dimer levels. Conclusions: In acutely ill patients with CLD, there are strong and consistent associations between TEG measures of clot formation and clot strength and conventional fibrinogen levels. There are weak and/or inconsistent associations between TEG and all other conventional measures of coagulation.
|
|
| 8. |
- Ruuskanen, T. M., et al.
(författare)
-
Concentrations and fluxes of aerosol particles during the LAPBIAT measurement campaign at Varrio field station
- 2007
-
Ingår i: Atmospheric Chemistry And Physics. - 1680-7316 .- 1680-7324. ; 7:14, s. 3683-3700
-
Tidskriftsartikel (refereegranskat)abstract
- The LAPBIAT measurement campaign took place in the Varrio SMEAR I measurement station located in Eastern Lapland in the spring of 2003 between 26 April and 11 May. In this paper we describe the measurement campaign, concentrations and fluxes of aerosol particles, air ions and trace gases, paying special attention to an aerosol particle formation event broken by a air mass change from a clean Arctic air mass with new particle formation to polluted one approaching from industrial areas of Kola Peninsula, Russia, lacking new particle formation. Aerosol particle number flux measurements show strong downward fluxes during that time. Concentrations of coarse aerosol particles were high for 1-2 days before the nucleation event (i.e. 28-29 April), very low immediately before and during the observed aerosol particle formation event (30 April) and increased moderately from the moment of sudden break of the event. In general particle deposition measurements based on snow samples show the same changes. Measurements of the mobility distribution of air ions showed elevated concentrations of intermediate air ions during the particle formation event. We estimated the growth rates in the nucleation mode size range. For particles <10 nm, the growth rate increases with size on 30 April. Dispersion modelling made with model SILAM support the conclusion that the nucleation event was interrupted by an outbreak of sulphate-rich air mass in the evening of 30 April that originated from the industry at Kola Peninsula, Russia. The results of this campaign highlight the need for detailed research in atmospheric transport of air constituents for understanding the aerosol dynamics.
|
|
| 9. |
- Venkatesan, M, et al.
(författare)
-
Erratum
- 2019
-
Ingår i: The American journal of tropical medicine and hygiene. - : American Society of Tropical Medicine and Hygiene. - 1476-1645 .- 0002-9637. ; 100:3, s. 766-766
-
Tidskriftsartikel (refereegranskat)
|
|
| 10. |
- Baranzahi, Amir, et al.
(författare)
-
Response of metal-oxide-silicon carbide sensors to simulated and real exhaust gases
- 1997
-
Ingår i: Sensors and actuators. B, Chemical. - : Elsevier. - 0925-4005 .- 1873-3077. ; 43:1-3, s. 52-59
-
Tidskriftsartikel (refereegranskat)abstract
- Field effect devices based on catalytic metal-oxide-silicon carbide (MOSiC) structures can be used as high temperature gas sensors. The devices are sensitive to hydrocarbons and hydrogen and can be operated up to at least 900 degrees C, which make them suitable for several combustion applications, Simulated and real exhaust gases from a car engine have been studied at sensor temperatures from 200 to 650 degrees C, and it was round that the sensor signal is high for excess hydrocarbon and low for excess oxygen. The response time is less than 100 ms and only a small degradation of the devices was observed after several days of operation. The devices also react to changes of the gas composition In the fuel-rich and fuel-lean region. The devices show an interesting temperature dependence in the fuel rich region.
|
|
