hig.sePublications
Change search
Link to record
Permanent link

Direct link
Rezasson, Reza
Alternative names
Publications (10 of 32) Show all publications
Rezasson, R., Zhou, T., Burvall, A., Lindgren, J., Fröjdh, C., Hertz, H. M. & Norlin, B. (2023). A fast and non-destructive alternative to the burnout method for paperboard quality inspections using phase-contrast X-ray imaging. TAPPI Journal, 22(2), 99-106
Open this publication in new window or tab >>A fast and non-destructive alternative to the burnout method for paperboard quality inspections using phase-contrast X-ray imaging
Show others...
2023 (English)In: TAPPI Journal, ISSN 0734-1415, Vol. 22, no 2, p. 99-106Article in journal (Refereed) Published
Abstract [en]

An X-ray based quality inspection method for paperboard was implemented and tested as a fastand non-destructive alternative to the burnout method. An argument against X-ray imaging for inspection of paperand paperboard has been that X-ray absorption is low in paper. To overcome this limitation, we used phase-contrastX-ray imaging (PCXI), which gives higher contrast than conventional attenuation-based imaging for low-absorbingmaterials such as paper. The suggested PCXI method was applied to previously prepared and quality rated samplesusing the burnout method.

A strong similarity between the burnout images and the PCXI images was observed. In conclusion, further devel-opment of the phase-contrast X-ray method would provide an interesting option for replacing or complementing thestandard burnout method.

Place, publisher, year, edition, pages
TAPPI, 2023
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Research subject
Intelligent Industry
Identifiers
urn:nbn:se:hig:diva-41152 (URN)10.32964/tj22.2.99 (DOI)2-s2.0-85151141048 (Scopus ID)
Available from: 2023-03-13 Created: 2023-03-13 Last updated: 2023-04-13Bibliographically approved
Reza, S. (2022). Universities should focus on intellectual diversity. Universitetsläraren (10-okt)
Open this publication in new window or tab >>Universities should focus on intellectual diversity
2022 (English)In: Universitetsläraren, ISSN 0282-4973, no 10-oktArticle in journal (Other (popular science, discussion, etc.)) Published
Place, publisher, year, edition, pages
SULF, 2022
National Category
Educational Sciences
Identifiers
urn:nbn:se:hig:diva-41052 (URN)
Available from: 2023-02-08 Created: 2023-02-08 Last updated: 2023-02-10Bibliographically approved
Reza, S. (2021). Corona has triggered a third wave of distance education. Universitetsläraren (26-apr)
Open this publication in new window or tab >>Corona has triggered a third wave of distance education
2021 (English)In: Universitetsläraren, ISSN 0282-4973, no 26-aprArticle in journal (Other (popular science, discussion, etc.)) Published
Place, publisher, year, edition, pages
SULF, 2021
National Category
Educational Sciences
Identifiers
urn:nbn:se:hig:diva-37273 (URN)
Available from: 2021-10-26 Created: 2021-10-26 Last updated: 2021-10-26Bibliographically approved
An, S., Reza, S., Norlin, B., Fröjdh, C. & Thungström, G. (2021). Signal-to-noise ratio optimization in X-ray fluorescence spectrometry for chromium contamination analysis. Talanta: The International Journal of Pure and Applied Analytical Chemistry, 230, Article ID 122236.
Open this publication in new window or tab >>Signal-to-noise ratio optimization in X-ray fluorescence spectrometry for chromium contamination analysis
Show others...
2021 (English)In: Talanta: The International Journal of Pure and Applied Analytical Chemistry, ISSN 0039-9140, E-ISSN 1873-3573, Vol. 230, article id 122236Article in journal (Refereed) Published
Abstract [en]

In most cases, direct X-ray fluorescence (XRF) analysis of solutions entails technical difficulties due to a high X-ray scattering background resulting in a spectrum with a poor signal-to-noise ratio (SNR). Key factors that determine the sensitivity of the method are the energy resolution of the detector and the amount of scattered radiation in the energy range of interest. Limiting the width of the primary spectrum by the use of secondary targets, or filters, can greatly improve the sensitivity for specific portions of the spectrum. This paper demonstrates a potential method for SNR optimization in direct XRF analysis of chromium (Cr) contamination. The suggested method requires minimal sample preparation and achieves higher sensitivity compared to existing direct XRF analysis. Two states of samples, fly ash and leachate from municipal solid waste incineration, were investigated. The effects of filter material, its absorption edge and filter thickness were analyzed using the combination of Monte Carlo N-Particle (MCNP) code and energy-dispersive XRF spectrometry. The applied filter removes primary photons with energies interfering with fluorescence photons from the element of interest, thus results in lower background scattering in the spectrum. The SNR of Cr peak increases with filter thickness and reaches a saturation value when further increased thickness only increases the measurement time. Measurements and simulations show that a Cu filter with a thickness between 100 μm and 140 μm is optimal for detecting Cr by taking into account both the SNR and the exposure time. With direct XRF analysis for solutions, the limit of quantitation (LOQ) of the achieved system was 0.32 mg/L for Cr, which is well below the allowed standard limitation for landfills in Sweden. This work shows that XRF can gain enough sensitivity for direct monitoring to certify that the Cr content in leachate is below environmental limits.

Place, publisher, year, edition, pages
Elsevier, 2021
Keywords
Chromium, Environmental monitoring, Hazardous materials, Limit of quantitation (LOQ), Waste management, X-ray fluorescence analysis (XRF)
National Category
Physical Sciences Chemical Sciences
Identifiers
urn:nbn:se:hig:diva-35554 (URN)10.1016/j.talanta.2021.122236 (DOI)000657143300001 ()2-s2.0-85103402317 (Scopus ID)
Available from: 2021-04-07 Created: 2021-04-07 Last updated: 2021-06-17Bibliographically approved
Niskanen, I., Forsberg, V., Zakrisson, D., Reza, S., Hummelgård, M., Andres, B., . . . Thungström, G. (2019). Determination of nanoparticle size using Rayleigh approximation and Mie theory. Chemical Engineering Science, 201(29), 222-229
Open this publication in new window or tab >>Determination of nanoparticle size using Rayleigh approximation and Mie theory
Show others...
2019 (English)In: Chemical Engineering Science, ISSN 0009-2509, E-ISSN 1873-4405, Vol. 201, no 29, p. 222-229Article in journal (Refereed) Published
Abstract [en]

Accurate determination of the size of nanoparticles has an important role in many different scientific and industrial purposes, such as in material, medical and environment sciences, colloidal chemistry and astrophysics. We describe an effective optical method to determine the size of nanoparticles by analysis of transmission and scattering of visible spectral range data from a designed UV-Vis multi-spectrophotometer. The size of the nanoparticles was calculated from the extinction cross section of the particles using Rayleigh approximation and Mie theory. We validated the method using polystyrene nanospheres, cellulose nanofibrils, and cellulose nanocrystals. A good agreement was achieved through graphical analysis between measured extinction cross section values and theoretical Rayleigh approximation and Mie theory predictions for the sizes of polystyrene nanospheres at wavelength range 450 - 750 nm. Provided that Rayleigh approximation's forward scattering (FS)/back scattering (BS) ratio was smaller than 1.3 and Mie theory's FS/BS ratio was smaller than 1.8. A good fit for the hydrodynamic diameter of nanocellulose was achieved using the Mie theory and Rayleigh approximation. However, due to the high aspect ratio of nanocellulose, the obtained results do not directly reflect the actual cross-sectional diameters of the nanocellulose. Overall, the method is a fast, relatively easy, and simple technique to determine the size of a particle by a spectrophotometer. Consequently, the method can be utilized for example in production and quality control purposes as well as for research and development applications.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
Nanoparticles, size, Rayleigh approximation, Mie theory, spectrophotometer, nanocellulose
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:hig:diva-37230 (URN)10.1016/j.ces.2019.02.020 (DOI)
Available from: 2021-10-22 Created: 2021-10-22 Last updated: 2021-10-22Bibliographically approved
Reza, S. (2019). Stressed in a small group or university?: Think Big!. Universitetsläraren (11-feb)
Open this publication in new window or tab >>Stressed in a small group or university?: Think Big!
2019 (English)In: Universitetsläraren, ISSN 0282-4973, no 11-febArticle in journal (Other (popular science, discussion, etc.)) Published
Place, publisher, year, edition, pages
Sveriges universitetslärare och forskares (SULF) medlemstidning, 2019
National Category
Educational Sciences
Identifiers
urn:nbn:se:hig:diva-37231 (URN)
Available from: 2021-10-22 Created: 2021-10-22 Last updated: 2021-10-22Bibliographically approved
Norlin, B., Reza, S., Fröjdh, C. & Nordin, T. (2018). Precision scan-imaging for paperboard quality inspection utilizing X-ray fluorescence. Journal of Instrumentation, 13(1), Article ID C01021.
Open this publication in new window or tab >>Precision scan-imaging for paperboard quality inspection utilizing X-ray fluorescence
2018 (English)In: Journal of Instrumentation, ISSN 1748-0221, E-ISSN 1748-0221, Vol. 13, no 1, article id C01021Article in journal (Refereed) Published
Abstract [en]

Paperboard is typically made up of a core of cellulose fibers [C6H10O5] and a coating layer of [CaCO3]. The uniformity of these layers is a critical parameter for the printing quality. Current quality control methods include chemistry based visual inspection methods as well as X-ray based methods to measure the coating thickness. In this work we combine the X-ray fluorescence signals from the Ca atoms (3.7 keV) in the coating and from a Cu target (8.0 keV) placed behind the paper to simultaneously measure both the coating and the fibers. Cu was selected as the target material since its fluorescence signal is well separated from the Ca signal while its fluorescence's still are absorbed sufficiently in the paper. A laboratory scale setup is built using stepper motors, a silicon drift detector based spectrometer and a collimated X-ray beam. The spectroscopic image is retrieved by scanning the paperboard surface and registering the fluorescence signals from Ca and Cu. The exposure time for this type of setups can be significantly improved by implementing spectroscopic imaging sensors. The material contents in the layers can then be retrieved from the absolute and relative intensities of these two signals.

Place, publisher, year, edition, pages
IOP, 2018
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:hig:diva-37232 (URN)10.1088/1748-0221/13/01/C01021 (DOI)
Available from: 2021-10-22 Created: 2021-10-22 Last updated: 2021-10-22Bibliographically approved
Olsen, M., Örtegren, J., Zhang, R., Reza, S., Andersson, H. & Olin, H. (2018). Schottky model for triboelectric temperature dependence. Scientific Reports, 8(1), Article ID 5293.
Open this publication in new window or tab >>Schottky model for triboelectric temperature dependence
Show others...
2018 (English)In: Scientific Reports, E-ISSN 2045-2322, Vol. 8, no 1, article id 5293Article in journal (Refereed) Published
Abstract [en]

The triboelectric effect, charging by contact, is the working principle in a device called a triboelectric nanogenerator. They are used as efficient energy transducers in energy harvesting. In such generators the charging of surfaces at contact is followed by a separation of the surfaces increasing the electrical energy which can subsequently be used. Different materials have different triboelectric potentials leading to charging at contact. The temperature dependence of the charging has just recently been studied: the triboelectric effect is decreasing with temperature for a generator of Al-PTFE-Cu. Here, we suggest a mechanism to explain this effect assuming ion transfer using a two-level Schottky model where the two levels corresponds to the two surfaces. The difference in binding energy for ions on the two surfaces then enters the formula for charging. We fit the triboelectric power density as a function of temperature obtained from a two-level Schottky model to measured data for nanogenerators made of Al-PTFE-Cu found in three references. We obtain an average separation energy corresponding to a temperature of 365 K which is of the right magnitude for physically adsorbed atoms. We anticipate that this model could be used for many types of triboelectric nanogenerators.

National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:hig:diva-37233 (URN)10.1038/s41598-018-23666-y (DOI)
Available from: 2021-10-22 Created: 2021-10-22 Last updated: 2022-09-15Bibliographically approved
Reza, S. (2018). Students are stories – let us recognize them. Universitetsläraren (12-feb)
Open this publication in new window or tab >>Students are stories – let us recognize them
2018 (English)In: Universitetsläraren, ISSN 0282-4973, no 12-febArticle in journal (Other (popular science, discussion, etc.)) Published
Place, publisher, year, edition, pages
Sveriges universitetslärare och forskares (SULF) medlemstidning, 2018
National Category
Educational Sciences
Identifiers
urn:nbn:se:hig:diva-37234 (URN)
Available from: 2021-10-22 Created: 2021-10-22 Last updated: 2021-10-22Bibliographically approved
Reza, S. (2018). Unacknowledged supervisors – superheroes without capes. Universitetsläraren (24-sep)
Open this publication in new window or tab >>Unacknowledged supervisors – superheroes without capes
2018 (English)In: Universitetsläraren, ISSN 0282-4973, no 24-sepArticle in journal (Other (popular science, discussion, etc.)) Published
Place, publisher, year, edition, pages
Sveriges universitetslärare och forskares (SULF) medlemstidning, 2018
National Category
Educational Sciences
Identifiers
urn:nbn:se:hig:diva-37235 (URN)
Available from: 2021-10-22 Created: 2021-10-22 Last updated: 2021-10-22Bibliographically approved
Organisations

Search in DiVA

Show all publications