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Your search keyword '"O'Farrell, Marion"' showing total 8 results
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8 results on '"O'Farrell, Marion"'

2. Measurements of droplets from singing, laughing, reciting poetry, and playing wind instruments

Author

Dunker, Tim, Tschudi, Jon, and O'Farrell, Marion

Subjects
Physics - Popular Physics, Physics - Fluid Dynamics
Abstract

We present initial results from measurements of exhaled droplets by two singers during singing, speaking, laughing, and recitation of poetry. We also conducted measurements with a flute, a clarinet, a tuba, and only the tuba's mouthpiece. To be able to image and track droplets, we have developed and built a portable measurement set-up. We have detected droplets with diameters of approximately 50 micrometre and above. We found that for a single subject, the largest amount of droplets are produced during singing, but that laughing can produce a comparable number of droplets. Speaking and recitation of poetry do not produce as many droplets. We repeated exercises at varying distances and found that the number of detected droplets decreased rapidly with increasing distance. Most droplets we detected follow a ballistic trajectory, and hit the ground after a distance of approximately 1 m. In case of the musical instruments, we did not detect droplets exiting a tuba and only few single droplets from a flute and a clarinet. A clarinet usually points downwards, such that droplets follow a downward trajectory and hit the ground after a short distance. The situation was different when the tubist used only the mouthpiece (that is, detached from the tuba) during warm-up while partially blocking the opening with a finger: in this case, many droplets were ejected from the mouthpiece. These followed ballistic trajectories at different speeds, with some droplets exiting the measurement volume. Two important limitations of this study are that (i) the sample size is very small, such that a statistical analysis is beyond our scope; and (ii) that we cannot draw conclusions about a possible risk of infection with COVID-19 when performing any of the said activities., Comment: The original project memo can be downloaded here: https://hdl.handle.net/11250/2888270. The are only minor differences between these two versions: (1) the slightly adapted title; (2) shortened abstract due to character constraint; and (3) an added sentence on supplemental material including the reference

Published
2022

7. Utvikling, kalibrering og verifisering av håndholdt vannmåler for klippfisk og saltfisk. Leveranse 4.2: Ferdig kalibrert håndholdt prototype instrument

Author

Wold, Jens Petter, Andersen, Petter Vejle, González Reboredo, Rodrigo, Tschudi, Jon, and O’Farrell, Marion

Abstract

I dette prosjektet har en målsetting vært å utvikle et håndholdt instrument for måling av vanninnhold i klippfisk. SINTEF Digital har utviklet en prototype av et NIR instrument som Nofima har testet ut. Resultatene er meget lovende. På et sett av 40 klippfisk, der vanninnholdet varierte fra 39.4 – 52.8%, kunne vi med dette instrumentet lage en kalibrering som kan anslå vanninnholdet med en nøyaktighet på ±1.3 %-poeng. Dette er omtrent like bra som det som oppnås med et stort og tungt NIR-instrument. Det er også vesentlig bedre enn det man normalt klarer å anslå ved tradisjonell vraking av fisken. Instrumentet er per i dag en prototype og videre utvikling er nødvendig dersom det skal bli tilgjengelig for næringa.

Published
2022

8. Fourier-transform infrared spectroscopy for characterization of liquid protein solutions: A comparison of two sampling techniques.

Author

Kafle, Bijay, Böcker, Ulrike, Wubshet, Sileshi Gizachew, Dankel, Katinka, Måge, Ingrid, O'Farrell, Marion, and Afseth, Nils Kristian

Subjects
*SAMPLING (Process), *PROTEIN hydrolysates, *PROCESS control systems, *FOURIER transform infrared spectroscopy, *MANUFACTURING processes
Abstract

Whereas industrial laboratory systems for Fourier-Transform Infrared (FTIR) spectroscopic characterization have been available for decades, dedicated FTIR solutions for in-line process control or for industrial at-line analysis of protein quality are still scarce. Thus, the present study aimed to compare two industrially viable sampling techniques, namely attenuated total reflectance (ATR) and dry film FTIR spectroscopy, for qualitative and quantitative analysis of liquid protein solutions. For this purpose, two sample sets were acquired: set 1 consisted of 95 protein hydrolysate samples produced in the laboratory from salmon processing by-products, and set 2 consisted of 133 protein hydrolysate samples obtained from an industrial processing plant of poultry by-products. Average molecular weights (AMW) and Brix measurements of protein hydrolysates were used as reference values for obtaining regression models. AMW was predicted with higher accuracy and lower estimation errors using dry film FTIR compared to ATR measurements for both sample types. The difference in predictive performance was higher in poultry hydrolysates because the protein and tissue complexities are higher than in salmon hydrolysates, and information from the amide I region in the FTIR spectra is needed to provide good calibration results. ATR, on the other hand, was more reliable for the prediction of Brix values of protein hydrolysates. The study also showed that FTIR spectroscopy can be used to predict protein quality features of industrially produced protein hydrolysates with a sensitivity of high industrial relevance. Therefore, developing industrially viable portable instruments for at-line process analysis in the food, feed, and biotech industries is a natural next development stage. [Display omitted] • This is the first study to compare ATR and dry film FTIR spectroscopy for quantitative analysis of liquid protein solutions. • Dryfilm FTIR showed higher accuracy for prediction of average molecular weight (AMW) in liquid protein hydrolysates. • FTIR can be used to predict the AMW of industrial protein hydrolysates with a sensitivity of high industrial relevance. • ATR proved to be a more reliable method for the prediction of Brix values. [ABSTRACT FROM AUTHOR]

Published
2023
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