| 1. |
- Trigo, João Pedro, 1995, et al.
(författare)
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Mild blanching prior to pH-shift processing of Saccharina latissima retains protein extraction yields and amino acid levels of extracts while minimizing iodine content
- 2023
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Ingår i: Food Chemistry. - : Elsevier BV. - 0308-8146 .- 1873-7072. ; 404
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Tidskriftsartikel (refereegranskat)abstract
- The seaweed Saccharina latissima is often blanched to lower iodine levels, however, it is not known how blanching affects protein extraction. We assessed the effect of blanching or soaking (80/45/12 °C, 2 min) on protein yield and protein extract characteristics after pH-shift processing of S. latissima. Average protein yields and extract amino acid levels ranked treatments as follows: blanching-45 °C ∼ control > soaking ∼ blanching-80 °C. Although blanching-45 °C decreased protein solubilization yield at pH 12, it increased isoelectric protein precipitation yield at pH 2 (p < 0.05). The former could be explained by a higher ratio of large peptides/proteins in the blanched biomass as shown by HP-SEC, whereas the latter by blanching-induced lowering of ionic strength, as verified by a dialysis model. Moreover, blanching-45 °C yielded a protein extract with 49 % less iodine compared with the control extract. We recommend blanching-45 °C since it is effective at removing iodine and does not compromise total protein extraction yield.
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| 2. |
- Marra, Eva, et al.
(författare)
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Oxygen reduction reaction kinetics on a Pt thin layer electrode in AEMFC
- 2022
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Ingår i: Electrochimica Acta. - : Elsevier BV. - 0013-4686 .- 1873-3859. ; 435, s. 141376-141376
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Tidskriftsartikel (refereegranskat)abstract
- The study of the catalytic activity in a fuel cell is challenging, as mass transport, gas crossover and the counterelectrode are generally interfering. In this study, a Pt electrode consisting of a thin film deposited on the gasdiffusion layer was employed to study the oxygen reduction reaction (ORR) in an operating Anion Exchange Membrane Fuel Cell (AEMFC). The 2D Pt electrode was assembled together with a conventional porous Pt/Ccounter electrode and an extra Pt/C layer and membrane to reduce the H2 crossover. Polarization curves atdifferent O2 partial pressures were recorded and the resulting reproducible ORR activities were normalized withrespect to the active surface area (ECSA), obtained by CO stripping. As expected, decreasing the O2 partialpressure results in a negative shift in open circuit voltage (OCV), cell voltage and maximum attainable currentdensity. For cell voltages above 0.8 V a fairly constant Tafel slope of 60 mV dec−1 was recorded but at lowervoltages the slope increases rapidly. The observed Tafel slope can be explained by a theoretical model with anassociative mechanism where charge- and proton-transfer steps are decoupled, and the proton transfer is the rate-determining step. A reaction order of 1 with respect to O2 was obtained at 0.65 V which corresponds well withthe mechanism suggested above. Based on the obtained catalyst activities, the electrode performance is comparable to good porous electrodes found in the field. The methodology presented in this study is expected to beuseful in future kinetic studies of other catalysts for AEMFC.
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| 3. |
- Zubritskaya, Irina, 1984, et al.
(författare)
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Dynamically Tunable Optical Cavities with Embedded Nematic Liquid Crystalline Networks
- 2023
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Ingår i: Advanced Materials. - : Wiley. - 0935-9648 .- 1521-4095. ; 35:13
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Tidskriftsartikel (refereegranskat)abstract
- Tunable metal–insulator–metal (MIM) Fabry–Pérot (FP) cavities that can dynamically control light enable novel sensing, imaging and display applications. However, the realization of dynamic cavities incorporating stimuli-responsive materials poses a significant engineering challenge. Current approaches rely on refractive index modulation and suffer from low dynamic tunability, high losses, and limited spectral ranges, and require liquid and hazardous materials for operation. To overcome these challenges, a new tuning mechanism employing reversible mechanical adaptations of a polymer network is proposed, and dynamic tuning of optical resonances is demonstrated. Solid-state temperature-responsive optical coatings are developed by preparing a monodomain nematic liquid crystalline network (LCN) and are incorporated between metallic mirrors to form active optical microcavities. LCN microcavities offer large, reversible and highly linear spectral tuning of FP resonances reaching wavelength-shifts up to 40 nm via thermomechanical actuation while featuring outstanding repeatability and precision over more than 100 heating–cooling cycles. This degree of tunability allows for reversible switching between the reflective and the absorbing states of the device over the entire visible and near-infrared spectral regions, reaching large changes in reflectance with modulation efficiency ΔR = 79%.
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| 4. |
- Hammarström, Thomas, 1974
(författare)
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Evaluation of Different Waveforms to Study the Insulation Performance on Electrical Vehicle Motors
- 2022
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Ingår i: Annual Report - Conference on Electrical Insulation and Dielectric Phenomena, CEIDP. - 0084-9162. ; 2022-November, s. 439-442
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Konferensbidrag (refereegranskat)abstract
- The operational voltage used in electrical vehicles increases continuously and the work presented in this paper compares different waveforms to evaluate the electrical stress in the motor windings. The aim is to explore the inception and extinction voltage level for the appearance of partial discharges (PDIV & PDEV) to evaluate grade 2 motor insulations. This to find pros and cons behind different approaches such as when applying sinusoidal or square shaped waveforms. It is also discussed how much deviation in properties than can be expected for different insulation thickness. The paper shows that it is important to use a waveform which as much as possible resembles the voltage shape used in the actual application to properly evaluate the performance of the insulation system. It is also recommended to include measurements at elevated temperatures in the analysis.
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| 5. |
- Moreno-Garcia, D., et al.
(författare)
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A Resonant Graphene NEMS Vibrometer
- 2022
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Ingår i: Small. - : Wiley. - 1613-6810 .- 1613-6829. ; 18:28
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Tidskriftsartikel (refereegranskat)abstract
- Measuring vibrations is essential to ensuring building structural safety and machine stability. Predictive maintenance is a central internet of things (IoT) application within the new industrial revolution, where sustainability and performance increase over time are going to be paramount. To reduce the footprint and cost of vibration sensors while improving their performance, new sensor concepts are needed. Here, double-layer graphene membranes are utilized with a suspended silicon proof demonstrating their operation as resonant vibration sensors that show outstanding performance for a given footprint and proof mass. The unveiled sensing effect is based on resonant transduction and has important implications for experimental studies involving thin nano and micro mechanical resonators that are excited by an external shaker.
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| 6. |
- Arroyo-De Dompablo, M. Elena, et al.
(författare)
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Achievements, Challenges, and Prospects of Calcium Batteries
- 2020
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Ingår i: Chemical Reviews. - : American Chemical Society (ACS). - 0009-2665 .- 1520-6890. ; 120:14, s. 6331-6357
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Forskningsöversikt (refereegranskat)abstract
- This Review flows from past attempts to develop a (rechargeable) battery technology based on Ca via crucial breakthroughs to arrive at a comprehensive discussion of the current challenges at hand. The realization of a rechargeable Ca battery technology primarily requires identification and development of suitable electrodes and electrolytes, which is why we here cover the progress starting from the fundamental electrode/electrolyte requirements, concepts, materials, and compositions employed and finally a critical analysis of the state-of-the-art, allowing us to conclude with the particular roadblocks still existing. As for crucial breakthroughs, reversible plating and stripping of calcium at the metal-anode interface was achieved only recently and for very specific electrolyte formulations. Therefore, while much of the current research aims at finding suitable cathodes to achieve proof-of-concept for a full Ca battery, the spectrum of electrolytes researched is also expanded. Compatibility of cell components is essential, and to ensure this, proper characterization is needed, which requires design of a multitude of reliable experimental setups and sometimes methodology development beyond that of other next generation battery technologies. Finally, we conclude with recommendations for future strategies to make best use of the current advances in materials science combined with computational design, electrochemistry, and battery engineering, all to propel the Ca battery technology to reality and ultimately reach its full potential for energy storage.
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| 7. |
- Lang, Victoria Ashley, et al.
(författare)
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Hand Temperature Is Not Consistent With Illusory Strength During the Rubber Hand Illusion.
- 2021
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Ingår i: Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual International Conference. - 2694-0604. ; 2021, s. 1416-1418
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Tidskriftsartikel (refereegranskat)abstract
- The rubber hand illusion is known to invoke a sense of ownership of a rubber hand when a person watches the stroking of the rubber hand in synchrony with their own hidden hand. Quantification of the sense of ownership is traditionally performed with the rubber hand illusion questionnaire, but the search for reliable physiological measurements persists. Skin temperature has been previously suggested and debated as a biomarker for ownership. We investigated hand temperature as a measure of rubber hand illusory strength via thermal imaging of the hand during the rubber hand experiment. No relationship was found between reported illusory strength and skin temperature.Clinical Relevance- Our results indicate that skin temperature is not a suitable biomarker for rubber hand illusory strength.
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| 8. |
- Das, Oisik, et al.
(författare)
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Naturally-occurring bromophenol to develop fire retardant gluten biopolymers
- 2020
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Ingår i: Journal of Cleaner Production. - : Elsevier. - 0959-6526 .- 1879-1786. ; 243
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Tidskriftsartikel (refereegranskat)abstract
- The aim of the study was to impart fire retardancy in wheat gluten polymer through naturally-occurring additives such as lanosol. The fire properties of lanosol were compared with two other conventional brominated fire retardants (Tetrabromobisphenol A and Hexabromocyclododecane). Samples containing fire retardants and gluten were prepared through compression moulding process and then characterised for their fire and mechanical properties. All fire retardants enhanced the reaction-to-fire and thermal properties of gluten while generating V-0 (i.e. vertical position and self-extinguished) ratings in the UL-94 test. The presence of all the fire retardants increased the modulus of the gluten polymer but the fire retardant particles were detrimental for the tensile strength. Nevertheless, lanosol addition delayed ignition and lowered peak heat release rate of gluten by the maximum amount, thereby leading to relatively higher fire performance index (compared to the other fire retardants). Lanosol also allowed the gluten to create a dense char barrier layer during burning that impeded the transfer of heat and flammable volatiles. The fact that only 4 wt% lanosol was able to cause self-extinguishment under direct flame and reduce peak heat release rate by a significant 50% coupled with its inherent occurrence in nature, raises the question if lanosol can be a potential fire retardant in polymeric systems, although it is a bromophenol.
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| 9. |
- Zhou, Ming, et al.
(författare)
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Oligoamine ionic liquids supported on mesoporous microspheres for CO2 separation with good sorption kinetics and low cost
- 2020
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Ingår i: Journal of CO2 Utilization. - : Elsevier. - 2212-9820 .- 2212-9839. ; 39
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Tidskriftsartikel (refereegranskat)abstract
- Ionic liquids display good CO2 absorption capacity but poor absorption kinetics and high costs. In the present work, we show that these problems can be solved by impregnating the new low cost ionic liquid pentaethylenehexammonium chloride [PEHA][Cl] and the corresponding amine precursor on a low cost mesoporous microsphere support. Nitrogen adsorption/ desorption, high-resolution SEM and thermogravimetric analysis were employed to analyze the structural and thermal properties of the prepared sorbents. The CO2 adsorption and desorption performance was studied by column experiments and mathematical models were fitted to the data. The results showed that sorbents displayed excellent sorption kinetics and capacity, comparable to the best reports in the literature. In addition, the sorbents could be regenerated and displayed high thermal stability. Finally, the costs of the sorbents developed in the present work is much lower than previously reported sorbents. Therefore this novel supported IL system could be promising for industrial CO2 removal and recovery applications.
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| 10. |
- Stedt, Kristoffer, 1991, et al.
(författare)
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Post-harvest cultivation with seafood process waters improves protein levels of Ulva fenestrata while retaining important food sensory attributes
- 2022
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Ingår i: Frontiers in Marine Science. - : Frontiers Media SA. - 2296-7745.
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Tidskriftsartikel (refereegranskat)abstract
- Seaweed aquaculture can provide the growing human population with a sustainable source of proteins. Sea-based cultivation is an effective method for farming seaweeds on a large scale and can yield high biomass output. However, the quality and biochemical composition of the biomass is seasonally dependent, which limits the harvests to certain periods of the year. Here we show the possibility to extend the sea-based cultivation season of Ulva fenestrata when aiming for high protein levels, by post-harvest treatment in herring production process waters. We harvested U. fenestrata at an optimal period in terms of yield, but suboptimal in terms of protein content. We then cultivated the seaweed in onshore tank systems with the nutrient-rich process waters for 14 days. We monitored biomass yield, crude protein content, amino acid composition, and content of the health concerning metals arsenic, mercury, lead, and cadmium, as well as the sensory properties of the dried biomass. After cultivation in the process waters, biomass yields were 30 - 40% higher (210 – 230 g fresh weight) compared to in seawater (160 g fresh weight). Also, the crude protein and amino acid content increased three to five times in the process waters, reaching 12 - 17 and 15 – 21% dry weight, respectively. The protein enriched biomass followed food graded standards for heavy metal content, and consumption of the biomass does not exceed health based reference points. Additionally, no sensory attributes regarded as negative were found. This rapid, post-harvest treatment can help extend the cultivation season of sea-based seaweed farms, maximizing their output of sustainable proteins.
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