| 1. |
- Holmberg, Martin, et al.
(författare)
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Bacteria classification based on feature extraction from sensor data
- 1998
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Ingår i: Biotechnology Techniques. - : Kluwer Academic Publishers. - 0951-208X .- 1573-6784. ; 12:4, s. 319-324
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Tidskriftsartikel (refereegranskat)abstract
- Data evaluation and classification have been made on measurements by an electronic nose on the headspace of samples of different types of bacteria growing on petri dishes. The chosen groups were: Escherichia coli, Enterococcus sp., Proteus mirabilis, Pseudomonas aeruginosa, and Staphylococcus saprophytica. An approximation of the response curve by time was made and the parameters in the curve fit were taken as important features of the data set. A classification tree was used to extract the most important features. These features were then used in an artificial neural network for classification. Using the ‘leave-one-out’ method for validating the model, a classification rate of 76% was obtained
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| 2. |
- Holmin, Susanne, et al.
(författare)
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Investigation of Electrode Materials as Sensors in a Voltammetric Electronic Tongue
- 2002
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Ingår i: Electroanalysis. - Weinheim, Germany : Wiley-VCH Verlagsgesellschaft. - 1040-0397 .- 1521-4109. ; 14:12, s. 839-847
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Tidskriftsartikel (refereegranskat)abstract
- In this work different electrode materials were investigated as sensors in a voltammetric electronic tongue. Basically, the electronic tongue is based on the combination of nonspecific sensors (electrodes) and pattern recognition tools, for example principal component analysis (PCA). Copper. glassy carbon, nickel, palladium, silver, tin, titanium and zirconium together with more traditional electrode materials such as gold, iridium, and platinum were studied. Cyclic voitammetry was applied to study typical model reactions in solutions containing different electroactive compounds, like ascorbic acid, glucose, histidine and potassium hexacyanoferrate(II). Different sensitivity and selectivity were obtained with the electrodes. Large responses were for example found for the amino acid and the carbohydrate using the copper, nickel and silver electrode. Some of the electrodes were employed in multicomponent solutions, i.e., liquid washing detergents from different suppliers together with differential pulse voltammetry. Responses from the electrodes in combination with PCA showed that they separated the detergents to different extents. This was further used when information from the sensors was merged together for successful discrimination of the detergents. It was found that two detergents close to each other in the score plot were from the same supplier. Furthermore. scanning electron microscopy (SEM) was used to monitor surface changes at the nonnoble electrodes (copper, nickel, and silver).
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| 3. |
- Leffler, Tomas, 1962, et al.
(författare)
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Monitoring of bed material in a biomass fluidized bed boiler using an electronic tongue
- 2023
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Ingår i: Fuel. - : Elsevier BV. - 0016-2361 .- 1873-7153. ; 340
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Tidskriftsartikel (refereegranskat)abstract
- The thermal conversion of biomass fuel mixes in fluidized beds can cause agglomeration. To counteract agglomeration, bed material is gradually exchanged with virgin bed material, and this results in increased disposal of used bed material. Furthermore, the bed material exchange represents a costly option, as it involves a cost for virgin bed material, for landfill, and for unplanned downtime of the plant. This paper presents a novel method for the evaluation of bed material quality: the electronic tongue (ET). Evaluation of bed material quality can contribute toward decreasing the cost of unnecessary exchanges of bed material. The proposed method was tested on bed material sampled on an almost daily basis from a commercial fluidized bed boiler during several months of operation. A two-electrode ET was used for the evaluation of the bed material quality. The analysis relied on pulsed voltammetry measurements and multivariate data analysis with Principal Component Analysis (PCA). The results suggest that it is possible to follow bed material changes and that the ET, after further development, may be used to optimize the material flows connected to the bed material. Further research is being conducted to optimize the ET's performance and its application in monitoring bed material.
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| 4. |
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| 5. |
- Ausen, Dag, et al.
(författare)
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Foresight Biomedical Sensors
- 2007
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The foresight study on biomedical sensors has addressed different approaches with future use of biomedical sensors in the health care sector, like: How will biomedical sensors shape the healthcare systems of the future? How can they impact the quality and cost of healthcare and what are the business opportunities in the Nordic region?
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| 6. |
- Bjorklund, Robert, et al.
(författare)
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Continuous monitoring of yoghurt fermentation using a noble metal electrode array
- 2009
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Ingår i: International Journal of Food Science and Technology. - : Wiley. - 0950-5423 .- 1365-2621. ; 44:3, s. 635-640
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Tidskriftsartikel (refereegranskat)abstract
- An electrochemical probe containing gold, platinum and rhodium working electrodes was used to monitor yoghurt production in a pilot facility. Three commercial starting cultures at 40, 42 and 44 C transformed milk having 1.5% fat content to mild yoghurt products. The electrochemical changes in the broth during fermentation were recorded as current responses from pulse voltammetry over the electrodes. Principal component analysis of the responses generated two-dimensional score plots describing the qualitative fermentation progressions. Two distinct fermentation pathways were observed leading to similar final products. The pH was recorded during the fermentations and the data was used as reference values for creating a partial least squares model for prediction of pH as an example of a quantitative application for the sensor. The relative mean squared error for validation of the model using four probes interchangeably was about 2%. The probe was constructed of materials approved for use in the food industry and did not require a standard glass reference electrode.
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| 7. |
- Carlsson, Andreas, et al.
(författare)
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An electronic tongue as a tool for wet-end monitoring
- 2001
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Ingår i: Nordic Pulp & Paper Research Journal. - 0283-2631 .- 2000-0669. ; 16:4, s. 319-326
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Tidskriftsartikel (refereegranskat)abstract
- An electronic tongue based on voltammetry and multivariate signal analysis has been evaluated as a tool for characterisation of the chemistry of the wet-end of a paper machine. Measurements were performed on head-box furnish samples from a tissue machine. PLS models, based on electronic tongue data, were made of five reference parameters - pH, conductivity, cationic demand, zeta potential and turbidity. The correlation coefficients for predicted values were for all parameters higher than 0.88. Highly correlated reference parameters might be part of the explanation for the high correlation factors. Still the results, being based on data without e.g. drift compensation, indicate that the electronic tongue has very promising features as a tool for wet-end control. Flexibility, fast response and wide sensitivity spectra make the electronic tongue suitable for a variety of applications.
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| 8. |
- Carlsson, Jenny, 1977-, et al.
(författare)
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Biosensor discrimination of meat juice from various animals using a lectin panel and ellipsometry
- 2005
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Ingår i: Analytica Chimica Acta. - : Elsevier BV. - 0003-2670 .- 1873-4324. ; 547:2, s. 229-236
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Tidskriftsartikel (refereegranskat)abstract
- In this work, simple microcontact printed gold-wafers were used to make a lectin panel for investigation and discrimination of different meat juices from fresh meat of cattle, chicken, pig, cod, turkey and lamb. Seven different lectins were thus attached to gold surfaces using the streptavidin–biotin method. Lectins recognize and bind specifically to carbohydrate structures present on different proteins. The biorecognition was evaluated with null ellipsometry and the data obtained was related to an internal standard of lactoferrin. The data was evaluated with multivariate data analysis techniques to identify possible discrimination or grouping of data. Scanning ellipsometry was used for visualization of the binding pattern of the lectins and the meat juice proteins. The two-dimensional images obtained could be used to visualize the protein distribution, furthermore, to exclude anomalies. The results showed that the different meat juices from the six different species: cattle, chicken, pig, cod, turkey and lamb could be discriminated from each other. The results showed to be more repetitive for the mammalian meat juices. Using a simple model based on an artificial neuronal net, it was also possible to classify meat juices from the mammals investigated.
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| 9. |
- Carlsson, Jenny, 1977-, et al.
(författare)
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Detection of global glycosylation changes of serum proteins in type 1 diabetes using a lectin panel and multivariate data analysis
- 2008
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Ingår i: Talanta. - : Elsevier BV. - 0039-9140 .- 1873-3573. ; 76:2, s. 333-337
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Tidskriftsartikel (refereegranskat)abstract
- Global glycosylation changes of serum proteins in type 1 diabetic patients have in this paper been investigated based on the interaction of the saccharide moiety of serum proteins with different lectins. Lectins are proteins, which bind carbohydrates specifically and reversibly. Panels with lectins of various carbohydrate specificities were immobilized on gold surfaces. Sera from healthy individuals, newly diagnosed type 1 diabetes patients and type 1 diabetes patients having had the disease for 4–6 years, respectively, were applied to the lectin panel. The biorecognition was evaluated with null ellipsometry. Data obtained were related to an internal standard of lactoferrin. Multivariate data analysis (MVDA) techniques were used to analyze data. Principal component analysis showed that the lectin panel enabled discrimination between sera from the three different above-mentioned groups. Using an artificial neuronal net (ANN), it was possible to correctly categorize unknown serum samples into one of the three groups.
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| 10. |
- Carlsson, Jenny, 1977-, et al.
(författare)
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Investigation of sera from various species by using lectin affinity arrays and scanning ellipsometry
- 2005
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Ingår i: Analytica Chimica Acta. - : Elsevier BV. - 0003-2670 .- 1873-4324. ; 530:2, s. 167-171
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Tidskriftsartikel (refereegranskat)abstract
- Serum proteins of different species and of different human blood groups exhibit various protein glycosylation patterns. Sera from human, pig, sheep and guinea pig have been applied to a panel of eight different lectins immobilized on a gold wafer. The biorecognition has been evaluated with scanning ellipsometry and the two-dimensional matrices obtained have been treated with image analysis and MVDA for evaluation. The results showed a clear difference in protein binding pattern between the different species and thereby separation of the different sera could be made. Dendograms indicate that human and pig sera are the most related of the four different sera investigated.
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