| 1. |
- Forsberg, Pontus, et al.
(author)
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Diamond grating waveplates
- 2016
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In: Optical Materials Express. - : Optical Society of America. - 2159-3930 .- 2159-3930. ; 6:6, s. 2024-2030
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Journal article (peer-reviewed)abstract
- Two designs of diamond quarter-wave plates for CO2 lasers, based on the birefringence of sub-wavelength gratings, were manufactured and tested. In one design the grating was etched on the surface of a 300 mu m thick polycrystalline diamond substrate. The other consisted of a diamond grating hanging freely in air, suspended at the edges from a silicon frame. The free-hanging design, while more fragile, had several advantages both in terms of fabrication and performance such as a larger grating period, higher transmission, and no need for an antireflective treatment of the backside.
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| 3. |
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| 4. |
- Van Den Berg, F. D., et al.
(author)
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Product uniformity control - A research collaboration of european steel industries to non-destructive evaluation of microstructure and mechanical properties
- 2018
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In: Stud. Appl. Electromagn. Mech.. - : IOS Press. - 9781614998358 ; 43, s. 120-129
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Conference paper (peer-reviewed)abstract
- In steel manufacturing, the conventional method to determine the mechanical properties and microstructure is by offline, destructive (lab-)characterisation of sample material that is typically taken from the head or the tail of the coil. Since coils can be up to 7 km long, the samples are not always representative for the main coil body. Also, the time delay (typically a few days) between the actual production and the availability of the characterisation results implies that these results cannot be exploited for real-time adaptation of the process settings. Information about the microstructure and material properties can also be obtained from electromagnetic (EM) and ultrasonic (US) parameters, which can be measured in real-time, non-destructively, and over the full length of the steel strip product. With the aim to improve the consistency in product quality by use of inline EM and US measurements, a European project called "Product Uniformity Control" (PUC) has been set up as a broad collaboration between 4 major European Steel Manufacturers and 10 Universities / Research institutes. Using both numerical simulations and experimental characterisations, we study the inline measured EM and US parameters in regard of the microstructural and mechanical properties. In this way, we aim to establish an improved understanding of their mutual relationships, and to apply this knowledge in existing and new nondestructive evaluation techniques. In this paper, the concerted approach of modelling and experimental validation will be addressed, and results of this work will be shown in combination with inline measured data.
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| 5. |
- Asem, Heba, 1987-, et al.
(author)
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Functional nano-carriers for drug delivery by surface engineering of polymeric nanoparticles post-PISA
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Other publication (other academic/artistic)abstract
- Engineered polymeric nanoparticles (NPs) have been comprehensively explored as potential platforms for diagnosis and targeted therapy for several diseases including cancer. Herein, we designed functional poly(acrylic acid)-b-poly(butyl acrylate) (PAA-b-PBA) NPs using reversible addition-fragmentation chain-transfer (RAFT)-mediated emulsion polymerization via polymerization-induced self-assembly (PISA). The hydrophilic PAA-macroRAFT, forming a stabilizing shell (i.e. corona), was chain-extended using the hydrophobic monomer n-butyl acrylate (n-BA), resulting in stable, monodisperse and reproducible PAA-b-PBA NPs, typically having a diameter of 130 nm. Two approaches of surface engineering of the PAA-b-PBA NPs post-PISA were explored; a two-step and a one-step approach. In the two-step approach, the hydrophilic NP-shell corona was modified with allyl-groups under mild conditions using allylamine in water which resulted in stable allyl-functional NPs (allyl-NPs) suitable for further bio-conjugation. Their versatility was investigated by the subsequent conjugation of a thiol-functional fluorescent dye (BODIPY-SH) to the allyl-groups using click chemistry, in order to mimic the attachment of a thiol-functional target ligand. The average size and size distribution of the corresponding NPs did not change after BODIPY-conjugation. Neither the NPs nor allyl-NPs showed significant cytotoxicity towards RAW264.7 or MCF-7 cell lines, which indicates their desirable safety profile. A one-step approach to concurrently conjugate allyl-groups and a fluorescent dye (FITC) to the preformed PAA-b-PBA NPs was investigated. The cellular uptake of the FITC-NPs using J774A cells in vitro was found to be time- and concentration-dependent. The anti-cancer drug, doxorubicin, was efficiently (90%) encapsulated into the PAA-b-PBA NPs during NP formation. After a small burst release during the first two hours, a controlled release pattern over 7 days was observed. The present investigation demonstrates a potential method to functionalize polymeric NPs post-PISA to produce targeted drug delivery carriers.
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| 6. |
- Asem, H., et al.
(author)
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Functional Nanocarriers for Drug Delivery by Surface Engineering of Polymeric Nanoparticle Post-Polymerization-Induced Self-Assembly
- 2021
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In: ACS Applied Bio Materials. - : American Chemical Society. - 2576-6422. ; 4:1, s. 1045-1056
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Journal article (peer-reviewed)abstract
- Engineered polymeric nanoparticles (NPs) have been comprehensively explored as potential platforms for diagnosis and targeted therapy for several diseases including cancer. Herein, we designed functional poly(acrylic acid)-b-poly(butyl acrylate) (PAA-b-PBA) NPs using reversible addition-fragmentation chain-transfer (RAFT)-mediated emulsion polymerization via polymerization-induced self-assembly (PISA). The hydrophilic PAA-macroRAFT, forming a stabilizing shell (i.e., corona), was chain-extended using the hydrophobic monomer n-butyl acrylate (n-BA), resulting in stable, monodisperse, and reproducible PAA-b-PBA NPs, typically having a diameter of 130 nm. The surface engineering of the PAA-b-PBA NP post-PISA were explored using a two-step approach. The hydrophilic NP-shell corona was modified with allyl groups under mild conditions, using allylamine in water, which resulted in stable allyl-functional NPs (allyl-NPs) suitable for further bioconjugation. The allyl-NPs were subsequently conjugated with a thiol-functional fluorescent dye (BODIPY-SH) to the allyl groups using "thiol-ene"-click chemistry, to mimic the attachment of a thiol-functional target ligand. The successful attachment of BODIPY-SH to the allyl-NPs was corroborated by UV-vis spectroscopy, showing the characteristic absorbance of the BODIPY-fluorophore at 500 nm. Despite modification of NPs with allyl groups and attachment of BODIPY-SH, the NPs retained their colloidal stability and monodispersity as indicated by DLS. This demonstrates that post-PISA functionalization is a robust method for synthesizing functional NPs. Neither the NPs nor allyl-NPs showed significant cytotoxicity toward RAW264.7 or MCF-7 cell lines, which indicates their desirable safety profile. The cellular uptake of the NPs using J774A cells in vitro was found to be time and concentration dependent. The anti-cancer drug doxorubicin was efficiently (90%) encapsulated into the PAA-b-PBA NPs during NP formation. After a small initial burst release during the first 2 h, a controlled release pattern over 7 days was observed. The present investigation demonstrates a potential method for functionalizing polymeric NP post-PISA to produce carriers designed for targeted drug delivery.
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| 7. |
- Berg, Frenk van den, et al.
(author)
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How the EU project “Online Microstructure Analytics” advances inline sensing of microstructure during steel manufacturing
- 2023
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In: Research and Review Journal of Nondestructive Testing (ReJNDT). - Lisabon : NDT.net GmbH & Co. KG. - 2941-4989. ; 1:1
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Journal article (peer-reviewed)abstract
- Weight savings in mobility and transport are mandatory in order to reduce CO2 emissions and energy consumption. The steel industry offers weight saving solutions by a growing portfolio of Advanced High Strength Steel (AHSS) products. AHSS owe their strength to their largely refined and complex microstructures, containing multiple metallurgical phases. Optimal control of the thermo-mechanical processing of AHSS requires inline sensors for real-time monitoring of evolution and consistency of microstructure and material properties.
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| 8. |
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| 9. |
- Berg, Frenk van den, et al.
(author)
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Results of the European collaborative project "Product Uniformity Control" to improve the inline sensing of mechanical properties and microstructure of automotive steels
- 2018
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In: e-Journal of Nondestructive Testing (eJNDT). - 1435-4934. ; 23:8
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Journal article (peer-reviewed)abstract
- A European consortium consisting of four major steel manufacturers and ten academic technology institutes has conducted a research and development project, called “Product Uniformity Control“ (PUC) in the period 2013 to 2017. This project aimed to develop and improve non-destructive (inline) measurement techniques to characterise the (uniformity of the) microstructure of steel strip products. In this project, a multitude of strip steel samples from various stages of production have been collected from the four participating steel manufacturers. The samples have been characterised in various ways, namely on their (1) non-destructive measurement parameters using different techniques suited for inline evaluation, (2) fundamental ultrasonic and electromagnetic properties (wave speed, ultrasonic attenuation, magnetisation loops, coercive field), (3) tensile properties (stress-strain curves) and (4) microstructure (by optical micrographs and EBSD images). The correlations between these different characterisations will be addressed. Besides the experimental characterisation, a strong accent has been on modelling activities: during the project, fundamental models have been developed to describe, starting from 2D and 3D microstructures, the ultrasonic and magnetic properties, which are next used as input to sensor models that predict the output of the inline measurement systems. This contribution presents the recent results of experimental work, which underlines the importance of associated modelling studies for the interpretation of the measurement data for the benefit of inline characterisation of the mechanical properties complementary to traditional destructive tensile testing.
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| 10. |
- Broman, Axel, et al.
(author)
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Multinodal Acoustic Trapping Enables High Capacity and High Throughput Enrichment of Extracellular Vesicles and Microparticles in miRNA and MS Proteomics Studies
- 2021
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In: Analytical Chemistry. - : American Chemical Society (ACS). - 1520-6882 .- 0003-2700. ; 93:8, s. 3929-3937
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Journal article (peer-reviewed)abstract
- We report a new design of an acoustophoretic trapping device with significantly increased capacity and throughput, compared to current commercial acoustic trapping systems. Acoustic trapping enables nanoparticle and extracellular vesicle (EV) enrichment without ultracentrifugation. Current commercial acoustic trapping technology uses an acoustic single-node resonance and typically operates at flow rates <50 μL/min, which limits the processing of the larger samples. Here, we use a larger capillary that supports an acoustic multinode resonance, which increased the seed particle capacity 40 times and throughput 25-40 times compared to single-node systems. The resulting increase in capacity and throughput was demonstrated by isolation of nanogram amounts of microRNA from acoustically trapped urinary EVs within 10 min. Additionally, the improved trapping performance enabled isolation of extracellular vesicles for downstream mass spectrometry analysis. This was demonstrated by the differential protein abundance profiling of urine samples (1-3 mL), derived from the non-trapped versus trapped urine samples.
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