A large number of optical properties in paper and print are determined by measuring the light reflected from an illuminated paper surface. These measurements are interpreted through a model, and the one that has been in use in the paper industry since the 1930s is deficient in some respects.
“We discovered that this is because the light is reflected in different amounts in different directions in an unexpected way. Our new model can explain and cope with this,” says researcher Per Edström.
What made this new discovery possible is his research into numerical methods for effectively solving a class of integro-differential equations. This is a type of problem that has applications in such diverse spheres as the greenhouse effect, medical tomography, and light diffusion in diffuse media.
“The methods Per Edström has developed are not only original. They have also been shown to be robust, accurate, and extremely effective,” says Professor Mårten Gulliksson.
Developmental work has involved collaboration with several companies in the paper industry. There has been a great interest since increased knowledge in this field means greater competitiveness.
“We have already started to use the new model,” says Nils Pauler at M-Real’s Research Center in Örnsköldsvik in Sweden. “We hope it will help us understand different variations in the visual impression made by paper and print.”
“It should be pointed out that Per Edström’s dissertation involves a tremendously broad spectrum of subject areas. From an advanced formulation of the physical problem in mathematical form, which is extremely well rooted in applications, he develops a stable and effective software that can be directly put to use by the industry with great success. This is an impressive achievement that is seldom witnessed in the field of mathematics.”
These are the concluding remarks of Professor Mårten Gulliksson.
The dissertation is titled ”Mathematical Modeling and Numerical Tools for Simulation and Design of Light Scattering in Paper and Print.”
Lars Aronsson | alfa
Quick, Precise, but not Cold
17.05.2017 | Fraunhofer-Institut für Lasertechnik ILT
A laser for divers
03.05.2017 | Laser Zentrum Hannover e.V.
An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.
We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...
Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.
Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...
An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...
In the race to produce a quantum computer, a number of projects are seeking a way to create quantum bits -- or qubits -- that are stable, meaning they are not much affected by changes in their environment. This normally needs highly nonlinear non-dissipative elements capable of functioning at very low temperatures.
In pursuit of this goal, researchers at EPFL's Laboratory of Photonics and Quantum Measurements LPQM (STI/SB), have investigated a nonlinear graphene-based...
Dental plaque and the viscous brown slime in drainpipes are two familiar examples of bacterial biofilms. Removing such bacterial depositions from surfaces is...
23.05.2017 | Event News
22.05.2017 | Event News
17.05.2017 | Event News
23.05.2017 | Physics and Astronomy
23.05.2017 | Life Sciences
23.05.2017 | Medical Engineering