| 51. |
- Alijan Farzad Lahiji, Faezeh, et al.
(författare)
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Unusual tilted growth and epitaxial relationship of NaCl B1-structured NiO and CrN on r-plane Al2O3
- 2024
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Ingår i: Journal of Applied Physics. - : American Institute of Physics Inc.. - 0021-8979 .- 1089-7550. ; 135:6
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Tidskriftsartikel (refereegranskat)abstract
- Epitaxial NiO and CrN thin films were deposited on a single-crystal Al2O3(11¯02) (r-plane sapphire) using magnetron sputtering. The two materials were intentionally deposited into two different deposition chamber designs and under different conditions (temperature, pressure, gases, and energy of sputtered particles). Despite the differences in the deposition condition and material system, both materials had the same feature with uncommon tilted epitaxial growth. Through an in-depth x-ray diffraction analysis of the NaCl (B1)-structured materials on r-plane sapphire, the full twin domain epitaxial relations were determined and can be described as (110)NaCl(B1)∥(44¯03)Al2O3 and [11¯2]NaCl(B1)∥[1¯1¯20]Al2O3. This relationship differs from the previously observed orientation of (100)NaCl(B1)∥(11¯02)Al2O3 and [100]NaCl(B1)∥[101¯0]Al2O3. These results are of general relevance for the growth of the extended NaCl (B1)-structured cubic material family onto a r-plane sapphire substrate where similar epitaxial growth can be expected.
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| 52. |
- Beijer, Kristina, et al.
(författare)
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Removal of pharmaceuticals and unspecified contaminants in sewage treatment effluents by activated carbon filtration and ozonation : Evaluation using biomarker responses and chemical analysis
- 2017
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Ingår i: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 176, s. 342-351
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Tidskriftsartikel (refereegranskat)abstract
- Traces of active pharmaceutical ingredients (APIs) and other chemicals are demonstrated in effluents from sewage treatment plants (STPs) and they may affect quality of surface water and eventually drinking water. Treatment of effluents with granular activated carbon (GAC) or ozone to improve removal of APIs and other contaminants was evaluated at two Swedish STPs, Kappala and Uppsala (88 and 103 APIs analyzed). Biomarker responses in rainbow trout exposed to regular and additionally treated effluents were determined. GAC and ozone treatment removed 87-95% of the total concentrations of APIs detected. In Kappala, GAC removed 20 and ozonation (7 g O-3/m(3)) 21 of 24 APIs detected in regular effluent. In Uppsala, GAC removed 25 and ozonation (5.4 g O-3/m(3)) 15 of 25 APIs detected in effluent. GAC and ozonation also reduced biomarker responses caused by unidentified pollutants in STP effluent water. Elevated ethoxyresorufin-O-deethylase (EROD) activity in gills was observed in fish exposed to effluent in both STPs. Gene expression analysis carried out in Kappala showed increased concentrations of cytochrome P450 (CYP1A5 and CYP1C3) transcripts in gills and of CYP1As in liver of fish exposed to effluent. In fish exposed to GAC- or ozone-treated effluent water, gill EROD activity and expression of CYP1As and CYP1C3 in gills and liver were generally equal to or below levels in fish held in tap water. The joint application of chemical analysis and sensitive biomarkers proved useful for evaluating contaminant removal in STPs with new technologies.
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| 53. |
- Bergenholtz, Sa Schoug, et al.
(författare)
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A case study on stress preconditioning of a Lactobacillus strain prior to freeze-drying
- 2012
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Ingår i: Cryobiology. - : Elsevier BV. - 0011-2240 .- 1090-2392. ; 64:3, s. 152-159
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Tidskriftsartikel (refereegranskat)abstract
- Freeze-drying of bacterial cells with retained viability and activity after storage requires appropriate formulation, i.e. mixing of physiologically adapted cell populations with suitable protective agents, and control of the freeze-drying process. Product manufacturing may alter the clinical effects of probiotics and it is essential to identify and understand possible factor co-dependencies during manufacturing. The physical solid-state behavior of the formulation and the freeze-drying parameters are critical for bacterial survival and thus process optimization is important, independent of strain. However, the maximum yield achievable is also strain-specific and strain survival is governed by e.g. medium, cell type, physiological state, excipients used, and process. The use of preferred compatible solutes for cross-protection of Lactobacilli during industrial manufacturing may be a natural step to introduce robustness, but knowledge is lacking on how compatible solutes, such as betaine, influence formulation properties and cell survival. This study characterized betaine formulations, with and without sucrose, and tested these with the model lactic acid bacteria Lactobacillus coryniformis Si3. Betaine alone did not act as a lyo-protectant and thus betaine import prior to freeze-drying should be avoided. Differences in protective agents were analyzed by calorimetry, which proved to be a suitable tool for evaluating the characteristics of the freeze-dried end products.
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| 54. |
- Bergsåker, Henrik, et al.
(författare)
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Microscopically nonuniform deposition and deuterium retention in the divertor in JET with ITER-like wall
- 2015
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Ingår i: Journal of Nuclear Materials. - : Elsevier BV. - 0022-3115 .- 1873-4820. ; 463, s. 956-960
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Tidskriftsartikel (refereegranskat)abstract
- The divertor surfaces in JET with ITER-like wall (ILW) have been studied using micro ion beam analysis (mu-IBA) methods and scanning electron microscopy (SEM). Deposited layers with beryllium as main constituent had been formed during plasma operations through 2011-2012. The deuterium trapping and impurity deposition were non-uniform, frequently enhanced within pits, cracks and valleys, regions reaching in size from 10 mu m to 200 mu m. The impurity deposition and fuel retention were correlated with the surface slope with respect to the direction of ion incidence. Typically more than 70% of the total measured areal density of trapped D was found in less than 30% of the surface area. This is of consequence for the interpretation of other surface analyses and in extrapolation from fuel retention in JET with ITER-like wall and rough divertor surfaces to ITER with smoother surfaces.
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| 55. |
- Carinelli, S., et al.
(författare)
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Yoctomole electrochemical genosensing of Ebola virus cDNA by rolling circle and circle to circle amplification
- 2017
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Ingår i: Biosensors & bioelectronics. - : Elsevier BV. - 0956-5663 .- 1873-4235. ; 93, s. 65-71
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Tidskriftsartikel (refereegranskat)abstract
- This work addresses the design of an Ebola diagnostic test involving a simple, rapid, specific and highly sensitive procedure based on isothermal amplification on magnetic particles with electrochemical readout. Ebola padlock probes were designed to detect a specific L-gene sequence present in the five most common Ebola species. Ebola cDNA was amplified by rolling circle amplification (RCA) on magnetic particles. Further re-amplification was performed by circle-to-circle amplification (C2CA) and the products were detected in a double-tagging approach using a biotinylated capture probe for immobilization on magnetic particles and a readout probe for electrochemical detection by square-wave voltammetry on commercial screen-printed electrodes. The electrochemical genosensor was able to detect as low as 200 ymol, corresponding to 120 cDNA molecules of L-gene Ebola virus with a limit of detection of 33 cDNA molecules. The isothermal double-amplification procedure by C2CA combined with the electrochemical readout and the magnetic actuation enables the high sensitivity, resulting in a rapid, inexpensive, robust and user-friendly sensing strategy that offers a promising approach for the primary care in low resource settings, especially in less developed countries.
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| 56. |
- Dong, Yihui, et al.
(författare)
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Determination of the small amount of proteins interacting with TiO2 nanotubes by AFM-measurement
- 2019
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Ingår i: Biomaterials. - : Elsevier. - 0142-9612 .- 1878-5905. ; 192, s. 368-376
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Tidskriftsartikel (refereegranskat)abstract
- Detecting the small amounts of proteins interacting effectively with the solid film electrodes surface still remains a challenge. To address this, in this work, a new approach was proposed by the combination of the adhesion forces and the molecular interaction measured with AFM. Cytochrome c (Cyt C) interacting effectively with TiO2 nanotube arrays (TNAs) was chosen as a probe. The amounts of Cyt C molecules interacting effectively on TNAs surface (CTNA) range from 5.5×10-12 to 7.0×10-12 mol/cm2 (68.2-86.8 ng/cm2) and they are comparable with the values obtained by the electrochemistry method in the literature, in evidence of the accuracy of this AFM-based approach. The reliability of the proposed approach was further verified by conducting Surface Enhanced Raman Scattering (SERS) measurements and estimating the enhancement factor (EF). This interaction-based AFM approach can be used to accurately obtain the small amounts of adsorbed substances on the solid film electrodes surface in the applications such as biosensors, biocatalysis, and drug delivery, etc.
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| 57. |
- Fachrizal, Reza, 1993-
(författare)
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Synergy between Residential Electric Vehicle Charging and Photovoltaic Power Generation through Smart Charging Schemes : Models for Self-Consumption and Hosting Capacity Assessments
- 2020
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The world is now in a transition towards a more sustainable future. Actions to reduce the green-house gases (GHG) emissions have been promoted and implemented globally, including switching to electric vehicles (EVs) and renewable energy technologies, such as solar photovoltaics (PV). This has led to a massive increase of EVs and PV adoption worldwide in the recent decade.However, large integration of EVs and PV in buildings and electricity distribution systems pose new challenges such as increased peak loads, power mismatch, component overloading, and voltage violations, etc. Improved synergy between EVs, PV and other building electricity load can overcome these challenges. Coordinated charging of EVs, or so-called EV smart charging, is believed to a promising solution to improve the synergy.This licentiate thesis investigates the synergy between residential EV charging and PV generation with the application of EV smart charging schemes. The investigation in this thesis was carried out on the individual building, community and distribution grid levels. Smart charging models with an objective to reduce the net-load (load - generation) variability in residential buildings were developed and simulated. Reducing the net-load variability implies both reducing the peak loads and increasing the self-consumption of local generation, which will also lead to improved power grid performance. Combined PV-EV grid hosting capacity was also assessed. Results show that smart charging schemes could improve the PV self-consumption and reduce the peak loads in buildings with EVs and PV systems. The PV self-consumption could be increased up to 8.7% and the peak load could be reduced down to 50%. The limited improvement on self-consumption was due to low EV availability at homes during midday when the solar power peaks. Results also show that EV smart charging could improve the grid performance such as reduce the grid losses and voltage violation occurrences. The smart charging schemes improve the grid hosting capacity for EVs significantly and for PV slightly. It can also be concluded that there was a slight positive correlation between PV and EV hosting capacity in the case of residential electricity distribution grids.
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| 58. |
- Feng, Yi, et al.
(författare)
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Flexible UHF resistive humidity sensors based on carbon nanotubes
- 2012
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Ingår i: IEEE Sensors Journal. - 1530-437X .- 1558-1748. ; 12:9, s. 2844-2850
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents the investigation of the resistive humidity-sensing properties of multi-walled carbon nanotubes (MWCNTs). MWCNTs functionalized by acid treatment (f-MWCNTs) exhibit rather high sensitivity in resistance toward humidity, owing to the presence of carboxylic groups on the nanotube surface. By integrating the f-MWCNTs resistor into a wireless sensor platform, flexible humidity sensors for ultra-high frequency applications are investigated. The operating frequency range of the sensor is dramatically increased from 600 MHz to 2 GHz by adjusting the resistor-electrodes' configuration. This enhancement is predominately attributed to the variation in parasitic capacitance between the resistor-electrodes.
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| 59. |
- Ghandour, Salim
(författare)
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Novel Materials and Implant Designs for the Treatment of Degenerative Disc Disease
- 2023
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The overarching objective of this thesis was to develop intervertebral implants for degenerated discs through design, fabrication, and mechanical validation. The research had four primary aims, each addressing different facets of implant development.The first aim was to design a structurally optimized fusion intervertebral cage capable of accommodating weak bioactive materials. Topology optimization was employed to design cages using titanium and calcium phosphate. The cage’s integrity was verified using finite element simulations, fabricated using additive manufacturing, and validated using ASTM F2077. Imaging techniques were utilized to assess the quality of the produced cages. These evaluations confirmed the mechanical reliability of the produced cage, able to incorporate around 75% in volume of a bioactive calcium phosphate material, protected by the titanium.The second aim was to develop a clinically relevant degeneration model for the biomechanical evaluation of percutaneous cement discoplasty (PCD). To this end, voids were generated in ovine functional spinal units (FSUs) using papain. The results were compared with clinical data where parameters such as void volume percentage, disc height, and morphology of the induced injury were assessed. FSUs were treated with PCD using bone cement, and mechanically evaluated under healthy, injured, and treated conditions to determine if PCD could stabilize the spinal segment. The void induced showed similar parameters compared to the clinical data. Further, the stability of the spine was significantly reduced after degeneration and restored after treatment, highlighting the effectiveness of the degeneration method and PCD treatment.The third aim was to evaluate the suitability of novel bone cements for their use in PCD. This study examined the tensile and fatigue properties of a low-modulus cement (VSLA) primarily intended for vertebroplasty. The formulation was tested in tensile and fatigue. VSLA showed a significant decrease in tensile and fatigue properties when compared to commercial cements. This study set a baseline for future low-modulus cements that may be tested for use in PCD.The fourth aim was to evaluate an alternative cement due to the low viscosity of VSLA, which may not be suitable for discoplasty. This study assessed the fatigue and long-term properties of a high-viscosity low-modulus cement (hv-LA-PMMA). The hv-LA-PMMA showed a significant reduction of mechanical and fatigue properties when compared to its commercial base. Notably, the fatigue properties were similar to those of the annulus fibrosus in the disc. Additionally, its high viscosity renders it a promising alternative to the bone cements currently utilized in PCD.In conclusion, this thesis successfully addressed the design, fabrication, and mechanical validation of two types of intervertebral implants for degenerated discs. The research outcomes contribute with valuable insights into the design of fusion cages, a degeneration model to evaluate PCD, and the assessment of low-modulus cements for use in PCD.
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| 60. |
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