| 1. |
- 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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| 2. |
- Asan, Noor Badariah, 1984-, et al.
(författare)
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Human Fat Tissue : A Microwave Communication Channel
- 2017
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Ingår i: 2017 First IEEE MTT-S International Microwave Bio Conference (IMBIOC). - : IEEE. - 9781538617137
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Konferensbidrag (refereegranskat)abstract
- In this paper, we present an approach for communication through human body tissue in the R-band frequency range. This study examines the ranges of microwave frequencies suitable for intra-body communication. The human body tissues are characterized with respect to their transmission properties using simulation modeling and phantom measurements. The variations in signal coupling with respect to different tissue thicknesses are studied. The simulation and phantom measurement results show that electromagnetic communication in the fat layer is viable with attenuation of approximately 2 dB per 20 mm.
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| 3. |
- Aidanpää, Jan-Olov, et al.
(författare)
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Developments in rotor dynamical modeling of hydropower units
- 2009
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Ingår i: Proceedings of the IUTAM Symposium on Emerging Trends in Rotor Dynamics. - Dordrecht : Encyclopedia of Global Archaeology/Springer Verlag. - 9789400700192
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Konferensbidrag (refereegranskat)
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| 4. |
- Amoignon, Olivier, et al.
(författare)
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Shape optimization for delay of laminar-turbulent transition
- 2006
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Ingår i: AIAA Journal. - : American Institute of Aeronautics and Astronautics (AIAA). - 0001-1452 .- 1533-385X. ; 44:5, s. 1009-1024
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Tidskriftsartikel (refereegranskat)abstract
- A method using gradient-based optimization is introduced for the design of wing profiles with the aim of natural laminar How, as well as minimum wave drag. The Euler equations of gasdynamics, the laminar boundary-layer equations for compressible flows on infinite swept wings, and the linear parabolized stability equations (PSE) are solved to analyze the evolution of convectively unstable disturbances. Laminar-turbulent transition is assumed to be delayed by minimizing a measure of the disturbance kinetic energy of a chosen disturbance, which is computed using the PSE. The shape gradients of the disturbance kinetic energy are computed based on the solutions of the adjoints of the state equations just named. Numerical tests are carried out to optimize the RAE 2822 airfoil with the aim to delay simultaneously the transition, reduce the pressure drag coefficient, and maintain the coefficients of lift and pitch moments. Constraints are also applied on the geometry. Results show a reduction of the total amplification of a large number of disturbances, which is assumed to represent a delay of the transition in the boundary layer. Because delay of the transition implies reduction of the viscous drag, the present method enables shape optimization to perform viscous drag reduction.
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| 5. |
- Asan, Noor Badariah, 1984-, et al.
(författare)
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Assessment of Blood Vessel Effect on Fat-Intrabody Communication Using Numerical and Ex-Vivo Models at 2.45 GHZ
- 2019
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Ingår i: IEEE Access. - : IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC. - 2169-3536. ; 7, s. 89886-89900
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Tidskriftsartikel (refereegranskat)abstract
- The potential offered by the intra-body communication (IBC) over the past few years has resulted in a spike of interest for the topic, specifically for medical applications. Fat-IBC is subsequently a novel alternative technique that utilizes fat tissue as a communication channel. This work aimed to identify such transmission medium and its performance in varying blood-vessel systems at 2.45 GHz, particularly in the context of the IBC and medical applications. It incorporated three-dimensional (3D) electromagnetic simulations and laboratory investigations that implemented models of blood vessels of varying orientations, sizes, and positions. Such investigations were undertaken by using ex-vivo porcine tissues and three blood-vessel system configurations. These configurations represent extreme cases of real-life scenarios that sufficiently elucidated their principal influence on the transmission. The blood-vessel models consisted of ex-vivo muscle tissues and copper rods. The results showed that the blood vessels crossing the channel vertically contributed to 5.1 dB and 17.1 dB signal losses for muscle and copper rods, respectively, which is the worst-case scenario in the context of fat-channel with perturbance. In contrast, blood vessels aligned-longitudinally in the channel have less effect and yielded 4.5 dB and 4.2 dB signal losses for muscle and copper rods, respectively. Meanwhile, the blood vessels crossing the channel horizontally displayed 3.4 dB and 1.9 dB signal losses for muscle and copper rods, respectively, which were the smallest losses among the configurations. The laboratory investigations were in agreement with the simulations. Thus, this work substantiated the fat-IBC signal transmission variability in the context of varying blood vessel configurations.
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| 6. |
- Asan, Noor Badariah, et al.
(författare)
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Characterization of the Fat Channel for Intra-Body Communication at R-Band Frequencies
- 2018
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Ingår i: Sensors. - : MDPI. - 1424-8220. ; 18:9
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, we investigate the use of fat tissue as a communication channel between in-body, implanted devices at R-band frequencies (1.7–2.6 GHz). The proposed fat channel is based on an anatomical model of the human body. We propose a novel probe that is optimized to efficiently radiate the R-band frequencies into the fat tissue. We use our probe to evaluate the path loss of the fat channel by studying the channel transmission coefficient over the R-band frequencies. We conduct extensive simulation studies and validate our results by experimentation on phantom and ex-vivo porcine tissue, with good agreement between simulations and experiments. We demonstrate a performance comparison between the fat channel and similar waveguide structures. Our characterization of the fat channel reveals propagation path loss of ∼0.7 dB and ∼1.9 dB per cm for phantom and ex-vivo porcine tissue, respectively. These results demonstrate that fat tissue can be used as a communication channel for high data rate intra-body networks.
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| 7. |
- Asan, Noor Badariah, 1984-, et al.
(författare)
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Effect of Thickness Inhomogeneity in Fat Tissue on In-Body Microwave Propagation
- 2018
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Ingår i: Proceedings of the 2018 IEEE/MTT-S International Microwave Biomedical Conference (IMBIOC). - Philadelphia, USA : IEEE. - 9781538659182 ; , s. 136-138
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Konferensbidrag (refereegranskat)abstract
- In recent studies, it has been found that fat tissue can be used as a microwave communication channel. In this article, the effect of thickness inhomogeneities in fat tissues on the performance of in-body microwave communication at 2.45 GHz is investigated using phantom models. We considered two models namely concave and convex geometrical fat distribution to account for the thickness inhomogeneities. The thickness of the fat tissue is varied from 5 mm to 45 mm and the Gap between the transmitter/receiver and the starting and ending of concavity/convexity is varied from 0 mm to 25 mm for a length of 100 mm to study the behavior in the microwave propagation. The phantoms of different geometries, concave and convex, are used in this work to validate the numerical studies. It was noticed that the convex model exhibited higher signal coupling by an amount of 1 dB (simulation) and 2 dB (measurement) compared to the concave model. From the study, it was observed that the signal transmission improves up to 30 mm thick fat and reaches a plateau when the thickness is increased further.
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| 8. |
- Asan, Noor Badariah, 1984-, et al.
(författare)
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Fat-IntraBody Communication at 5.8 GHz : Verification of Dynamic Body Movement Effects using Computer Simulation and Experiments
- 2021
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Ingår i: IEEE Access. - : IEEE. - 2169-3536. ; 9, s. 48429-48445
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents numerical modeling and experimental validation of the signal path loss at the 5.8 GHz Industrial, Scientific, and Medical (ISM) band, performed in the context of fat-intrabody communication (fat-IBC), a novel intrabody communication platform using the body-omnipresent fat tissue as the key wave-guiding medium. Such work extends our previous works at 2.0 and 2.4 GHz in the characterization of its performance in other useful frequency range. In addition, this paper also includes studies of both static and dynamic human body movements. In order to provide with a more comprehensive characterization of the communication performance at this frequency, this work focuses on investigating the path loss at different configurations of fat tissue thickness, antenna polarizations, and locations in the fat channel. We bring more realism to the experimental validation by using excised tissues from porcine cadaver as both their fat and muscle tissues have electromagnetic characteristics similar to those of human with respect to current state-of-art artificial phantom models. Moreover, for favorable signal excitation and reception in the fat-IBC model, we used topology optimized waveguide probes. These probes provide an almost flat response in the frequency range from 3.2 to 7.1 GHz which is higher than previous probes and improve the evaluation of the performance of the fat-IBC model. We also discuss various aspects of real-world scenarios by examining different models, particularly homogeneous multilayered skin, fat, and muscle tissue. To study the effect of dynamic body movements, we examine the impact of misalignment, both in space and in wave polarization, between implanted nodes. We show in particular that the use of fat-IBC techniques can be extended up in frequency to a broadband channel at 5.8 GHz.
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| 9. |
- Asan, Noor Badariah, 1984-, et al.
(författare)
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Impact of Blood Vessels on Data Packet Transmission Through the Fat Channel
- 2018
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Ingår i: 2018 IEEE INTERNATIONAL RF AND MICROWAVE CONFERENCE (RFM 2018). - : IEEE conference proceedings. - 9781538667200 - 9781538667194 - 9781538667217 ; , s. 196-198
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Konferensbidrag (refereegranskat)abstract
- The reliability of intra-body wireless communication systems is very important in medical applications to ensure the data transmission between implanted devices. In this paper, we present newly developed measurements to investigate the effect of blood vessels on the data packet reception through the fat tissue. We use an IEEE 802.15.4-based WBAN prototype to measure the packet reception rate (PRR) through a tissue-equivalent phantom model. The blood vessels are modelled using copper rods. We measure the PRR at the frequency 2.45 GHz for several power levels. The results revealed that the presence of blood vessels aligned with the fat channel has tiny influence on the PRR when measured over the range -25 dBm to 0 dBm power level and for different blood vessels positions. Our investigations show 97% successful PRR through a 10 cm length fat channel in presence of the blood vessels.
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| 10. |
- Geng, Zeyang, 1991, et al.
(författare)
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Bridging physics-based and equivalent circuit models for lithium-ion batteries
- 2021
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Ingår i: Electrochimica Acta. - : Elsevier BV. - 0013-4686 .- 1873-3859. ; 372
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Tidskriftsartikel (refereegranskat)abstract
- In this article, a novel implementation of a widely used pseudo-two-dimensional (P2D) model for lithium-ion battery simulation is presented with a transmission line circuit structure. This implementation represents an interplay between physical and equivalent circuit models. The discharge processes of an LiNi0.33Mn0.33Co0.33O2-graphite lithium-ion battery under different currents are simulated, and it is seen the results from the circuit model agree well with the results obtained from a physical simulation carried out in COMSOL Multiphysics, including both terminal voltage and concentration distributions. Finally we demonstrated how the circuit model can contribute to the understanding of the cell electrochemistry, exemplified by an analysis of the overpotential contributions by various processes.
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