Found 92 publications. Showing page 4 of 4:
2024
The aim of this project is to investigate and predict the quantified effect of indoor environment on pupils’ health in schools in Norway during the COVID-19 pandemic. The results are based on field measurements of the indoor environment in a Norwegian school. In addition, a survey (Mitt Inneklima) from NAAF was given to the pupils, and the result was investigated by using a machine learning model. From the field measurements it was found that the indoor temperature was generally too high, the relative humidity was too low, and the CO2- concentration was typically below 1000 ppm. The survey shows that more pupils are experiencing various indoor climate problems every week compared to the reference school for almost all of the parameters. By using machine learning, it is found that Too hot is an important feature for 11 of the 12 health problems, while Dry air is an important feature for nine of them.
2021
2024
This study aimed to assess whether building materials,
furniture, and user equipment are sources of pollution
that would influence the need for ventilation. Between
2017-2020, measurements were taken in four regular
classrooms in a low emitting school and four modular
classrooms in a prefabricated school. Weekly passive
sampling of volatile organic compounds (VOCs) and
aldehydes were carried out in the classrooms under
the following four conditions: 1) emptied, 2) furnished,
3) with furniture and user equipment, and 4) during
normal use. For the first three conditions, the
classrooms were measured with either no ventilation
or "low" airflow rates. Total VOC (TVOC)
concentrations were up to ten times higher in the
unventilated classroom at the prefabricated school
compared to classrooms at the low emitting school
(<450 µg/m3 for conditions 1-2). Our results show the
importance of selecting low emitting building
materials and proper ventilation.
2021
2018
2018
2022
Anodes fabricated from a single source coke were used for investigations of effect of porosity and surface roughness on the electrochemical performance in laboratory scale cells. In order to fabricate anodes differing in porosity, the production parameters were varied with two levels of mixing temperatures (150 and 210 °C) and three baking levels (underbaking at 1150°E, normal baking at 1260°E, overbaking at 1350°E). °E denotes the equivalent temperature which is a function of both the temperature the anode sees, and the time kept at this temperature. The low mixing anodes were more inhomogeneous with respect to both micro- and macroporosity, which can be attributed to the wetting between pitch and coke. After electrolysis, the real surface area of the low mixing anodes was about 13% higher than the high mixing anodes. Also, the low mixing electrodes had slightly larger electrochemically active surface area after electrolysis compared to the high mixing electrodes, as evidenced by higher capacitance measured at low current densities. Still, the mixing and equivalent baking temperatures did not affect the electrochemical overpotential at 1 A/cm2 to any significant extent. This could be understood from the 3D computed tomography images, which also showed that the electrolyte does not generally penetrate into the pores on the surface, penetration will depend on the size and shape of the pore.
2019
2025
2022