Fraunhofer Chalmers Research Centre for Industrial Mathematics
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BRICKS AGAIN - A study on the potential of masonry structures built from unused resources
No full textEffect from Combining Marine and Agricultural By-products during pH-shift Processing
No full textSeafood is an important and nutritious part of our diet, for which a high demand calls for new approaches to sustain aquatic food resources. Residuals emerging in seafood production are very nutrient-rich and among other things containing high levels of protein. For extraction of proteins, a processing method has been developed, referred to as pH-shift processing, where proteins are solubilized at acid or alkaline pH followed by precipitation at the isoelectric point (pI). However, due to a high content of pro-oxidants and lipids in seafood by-products, the issue of lipid oxidation can remain during processing.
The hypothesis behind this study, which is part of the Formas-funded CROSS-project, was that seaweed as well as residuals from processing of agricultural raw materials and shellfish, which comprise high levels of compounds with antioxidative, textural, pigmenting and other functional properties, could be added during pH-shift processing of fish by-products to improve the quality of the produced protein isolates. To investigate this hypothesis, herring and salmon filleting by-products were cross-processed with seaweed, shrimp peeling by-products and lingonberry press cake (referred to as “helpers”). Evaluations were made based on protein solubility, used volume of acid and base as well as protein yield in the pH-shift process. Total protein, moisture content, color and lipid oxidation products in the final protein isolate were also monitored.
Results revealed that cross-processing of the helpers with fish by-products had remarkable effects on the pH-shift processing yield and quality of the final protein isolate, although the exact effects were highly dependent on type of helper and fish by-product, as well as the employed process conditions. As examples, addition of helpers to the fish by-products in the first step of the process reduced the protein solubility and thereby the total protein yield. However, there were indications that new textures were achieved, e.g. with seaweed, and that lipid oxidation was prevented, e.g. with lingonberry press cake. Trials with adding lingonberry press cake in the second step of the process revealed that this by-product could completely replace the use of hydrochloric acid to precipitate proteins, and also, when added in this step, did not give rise to reductions in protein yield
On the geotechnical capacities of Sentinel-1A InSAR measurements over the Gothenburg area
No full textLamell- och Finita elementmetodernas osäkerheter vid släntmodellering - Faran i Göta älvdalen
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PET recycling via gasification - Influence of operating conditions on product distribution
No full textEU plans to achieve 100% plastic packaging reuse in 2040, and some new technologies have been proposed. Gasification is one of the promising technologies to convert plastic into syngas for heat production or chemicals synthesis process. This project focused on the thermoplastic that is widely used in textile fibre, film, and bottles – PET. Although PET bottle recycling is reliable, gasification could be an option for recycling contaminated and other PET products.
Proximate analysis was carried out by Thermogravimetric Analysis (TGA) to comprehend its thermal decomposition, obtaining volatiles and char. Gasification experiments were conducted in a lab scale bubbling fluidized bed with batch and continuous feeding operation. The batch experiments compared different plastics and gasifying agents. It was found that CO2 dominated the gas production at all agents, and steam can motivate H2 production. However, air cannot reduce tar formation significantly as literature stated. After that, continuous feeding experiments for steam gasification were designedtoinvestigatehowtemperature, residence time and steam/fuel ratio affect the distribution of gas and tar products in PET steam gasification. The results show the temperature is an essential condition parameter for gas and tar yield. The increasing temperature improved the gas yield and tar cracking.
The application of syngas produced by PET steam gasification was evaluated based on the experimental results. The highest energy conversion efficiency from PET and reacted steam to cold syngas was 29% at 800 ◦C, meaning that most of heat energy was lost. Fuel synthesis was analyzed by H2/CO ratio, and syngas products are more likely to be produced fuels by FT synthesis. Besides, the tar limitation of both power generation and fuel synthesis are very strict, but the tar concentrations in all cases are extremely high. Mixing with other plastics or biomass and better bed material could be solutions to promote syngas quality. Moreover, the mass balance analysis suggests 35% - 40% carbon was not detected, so sampling and measurement methods should be improved in the future research
Optimization of engine noise reduction measurement procedure
No full textA comfortable and quiet environment in the car cabin is a key component for the driving experience and safety. The noise generated in the cabin, from the engine
compartment, can be transmitted both via air-borne or structure-borne paths. The engine noise reduction measurement technique (ENR), takes into consideration only
the airborne sound.
The measurement technique is used before and after placing absorbers in the engine
compartment to compare the different transmitted levels. Therefore, it is fundamental to understand if the difference in the two results is due to the actual absorbers
or because of the uncertainties in the measurement procedure.
This Master thesis focuses on the robustness and precision of the method within the frequency range for internal combustion engines and Electric battery vehicles.
The available equipment and a new prototype of rugged pressure microphones from G.R.A.S Sound and Vibration have been used.
The smallest possible error within the method has been found to be equal to 1 dB and therefore also the precision of the method. The robustness of the method
for Combustion engine vehicle and Electric vehicle has been investigated and a safe frequency range has been found to be from 400 Hz to 8 kHz. In addition, an optimized number of microphones and their optimal location has been recommended.
According to the data and the analysis, the method can be considered robust within the safe frequency range. The procedure has also been improved, weighting less the
positions of the volume source, close to the windows, in the car compartment
