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Reza, Salim
Publications (10 of 28) Show all publications
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
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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.

Keywords
Nanoparticles, size, Rayleigh approximation, Mie theory, spectrophotometer, nanocellulose
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:miun:diva-35764 (URN)10.1016/j.ces.2019.02.020 (DOI)000462034900020 ()2-s2.0-85062846560 (Scopus ID)
Available from: 2019-03-08 Created: 2019-03-08 Last updated: 2019-05-20Bibliographically approved
Reza, S. (2019). Stressed in a small group or university? Think Big!. Universitetsläraren, Sveriges universitetslärare och forskares (SULF) medlemstidning
Open this publication in new window or tab >>Stressed in a small group or university? Think Big!
2019 (English)Other (Other (popular science, discussion, etc.))
Place, publisher, year, pages
Universitetsläraren, Sveriges universitetslärare och forskares (SULF) medlemstidning, 2019
National Category
Educational Sciences
Identifiers
urn:nbn:se:miun:diva-35614 (URN)
Note

Online 11 February, 2019

Available from: 2019-02-11 Created: 2019-02-11 Last updated: 2019-02-11Bibliographically approved
Norlin, B., Reza, S., Fröjdh, C. & Nordin, T. (2018). Precision scan-imaging for paperboard quality inspection utilizing X-ray fluorescence. Paper presented at 19th International Workshop on Radiation Imaging Detectors (IWORID2017), Krakow, Poland, 2-6 July, 2017. 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.

National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:miun:diva-32724 (URN)10.1088/1748-0221/13/01/C01021 (DOI)000422899200004 ()2-s2.0-85041817589 (Scopus ID)
Conference
19th International Workshop on Radiation Imaging Detectors (IWORID2017), Krakow, Poland, 2-6 July, 2017
Available from: 2018-01-22 Created: 2018-01-22 Last updated: 2018-02-26Bibliographically 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
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2018 (English)In: Scientific Reports, ISSN 2045-2322, 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:miun:diva-33379 (URN)10.1038/s41598-018-23666-y (DOI)000428518500004 ()2-s2.0-85044510140 (Scopus ID)
Available from: 2018-03-28 Created: 2018-03-28 Last updated: 2019-05-18Bibliographically approved
Reza, S. (2018). Students are stories – let us recognize them. Universitetsläraren, Sveriges universitetslärare och forskares (SULF) medlemstidning
Open this publication in new window or tab >>Students are stories – let us recognize them
2018 (English)Other (Other (popular science, discussion, etc.))
Place, publisher, year, pages
Universitetsläraren, Sveriges universitetslärare och forskares (SULF) medlemstidning, 2018
National Category
Educational Sciences
Identifiers
urn:nbn:se:miun:diva-32834 (URN)
Note

Tillgänglig online 12 februari 2018

Available from: 2018-02-12 Created: 2018-02-12 Last updated: 2018-02-12Bibliographically approved
Reza, S. (2018). Unacknowledged supervisors – superheroes without capes. Universitetsläraren, Sveriges universitetslärare och forskares (SULF) medlemstidning
Open this publication in new window or tab >>Unacknowledged supervisors – superheroes without capes
2018 (English)Other (Other (popular science, discussion, etc.))
Place, publisher, year, pages
Universitetsläraren, Sveriges universitetslärare och forskares (SULF) medlemstidning, 2018
National Category
Educational Sciences
Identifiers
urn:nbn:se:miun:diva-34487 (URN)
Note

Online 24 september 2018

Available from: 2018-09-24 Created: 2018-09-24 Last updated: 2018-09-24Bibliographically approved
Reza, S. (2017). Cultural contrasts affect the teacher–student relationship. Universitetsläraren, Sveriges universitetslärare och forskares (SULF) medlemstidning
Open this publication in new window or tab >>Cultural contrasts affect the teacher–student relationship
2017 (English)Other (Other (popular science, discussion, etc.))
Place, publisher, year, pages
Universitetsläraren, Sveriges universitetslärare och forskares (SULF) medlemstidning, 2017
National Category
Educational Sciences
Identifiers
urn:nbn:se:miun:diva-30542 (URN)STC (Local ID)STC (Archive number)STC (OAI)
Note

Online: 20 March 2017

Available from: 2017-03-31 Created: 2017-03-31 Last updated: 2017-09-04Bibliographically approved
Reza, S. (2017). In a non-hierarchical society far, far away from home …. Universitetsläraren, Sveriges universitetslärare och forskares (SULF) medlemstidning
Open this publication in new window or tab >>In a non-hierarchical society far, far away from home …
2017 (English)Other (Other (popular science, discussion, etc.))
Place, publisher, year, pages
Universitetsläraren, Sveriges universitetslärare och forskares (SULF) medlemstidning, 2017
National Category
Social Sciences
Identifiers
urn:nbn:se:miun:diva-31679 (URN)
Note

Online: 25 September 2017

Available from: 2017-09-27 Created: 2017-09-27 Last updated: 2017-09-27Bibliographically approved
Reza, S. (Ed.). (2017). Semiconductor Radiation Detectors: Technology and Applications. CRC Press
Open this publication in new window or tab >>Semiconductor Radiation Detectors: Technology and Applications
2017 (English)Collection (editor) (Refereed)
Abstract [en]

The aim of this book is to educate the reader on radiation detectors, from sensor to read-out electronics to application. Relatively new detector materials, such as CdZTe and Cr compensated GaAs, are introduced, along with emerging applications of radiation detectors. This X-ray technology has practical applications in medical, industrial, and security applications. It identifies materials based on their molecular composition, not densities as the traditional transmission equipment does. With chapters written by an international selection of authors from both academia and industry, the book covers a wide range of topics on radiation detectors, which will satisfy the needs of both beginners and experts in the field.

Place, publisher, year, edition, pages
CRC Press, 2017. p. 290
Series
Devices, Circuits, and Systems
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:miun:diva-31504 (URN)10.1201/9781315200729 (DOI)2-s2.0-85051814547 (Scopus ID)STC (Local ID)9781138710344 (ISBN)STC (Archive number)STC (OAI)
Available from: 2017-08-31 Created: 2017-08-31 Last updated: 2018-10-01Bibliographically approved
Norlin, B., Reza, S. & Fröjdh, C. (2017). X-ray fluorescence measurements of toxic metal content in ash from municipal solid waste incineration. In: 2016 IEEE Nuclear Science Symposium, Medical Imaging Conference and Room-Temperature Semiconductor Detector Workshop (NSS/MIC/RTSD): . Paper presented at 2016 IEEE Nuclear Science Symposium, Medical Imaging Conference and Room-Temperature Semiconductor Detector Workshop (NSS/MIC/RTSD), Strasbourg, France, 29 Oct.-6 Nov. 2016. IEEE, 2017-January, Article ID 8069695.
Open this publication in new window or tab >>X-ray fluorescence measurements of toxic metal content in ash from municipal solid waste incineration
2017 (English)In: 2016 IEEE Nuclear Science Symposium, Medical Imaging Conference and Room-Temperature Semiconductor Detector Workshop (NSS/MIC/RTSD), IEEE, 2017, Vol. 2017-January, article id 8069695Conference paper, Published paper (Refereed)
Abstract [en]

The vision of this paper is development of an online X-ray fluorescence method for monitoring of metal content in ash from municipal solid waste (MSW) incineration. With such measurements directly on site it is possible to optimize an ash washing process in incineration plants, allowing the fly ash to be stored in a landfill for non-hazardous waste. The presented X-ray fluorescence measurement assures that the measurement accuracy is sufficient for metal content monitoring. The actual measurement process is also fast enough to be possible to implement as an online measurement method. The optimal measurement setup is different for different metals. Several different metals might need environmental monitoring, which metals might vary over time due to systematic variations in waist content. Detection of a wide range of metals will require an X-ray source with variable voltage and multiple detectors.

Place, publisher, year, edition, pages
IEEE, 2017
National Category
Engineering and Technology
Identifiers
urn:nbn:se:miun:diva-31947 (URN)10.1109/NSSMIC.2016.8069695 (DOI)2-s2.0-85041723656 (Scopus ID)
Conference
2016 IEEE Nuclear Science Symposium, Medical Imaging Conference and Room-Temperature Semiconductor Detector Workshop (NSS/MIC/RTSD), Strasbourg, France, 29 Oct.-6 Nov. 2016
Available from: 2017-10-24 Created: 2017-10-24 Last updated: 2018-02-21Bibliographically approved
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