| 1. |
- Irshad, Muneeb, et al.
(författare)
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Evaluation of BaCo0.Fe-4(0).4Zr0.2-xNixO3-delta perovskite cathode using nickel as a sintering aid for IT-SOFC
- 2021
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Ingår i: RSC Advances. - : Royal Society of Chemistry. - 2046-2069. ; 11:24, s. 14475-14483
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Tidskriftsartikel (refereegranskat)abstract
- In this research work, BaCo0.Fe-4(0).4Zr0.2-xNixO3-delta (x = 0, 0.01, 0.02, 0.03, 0.04) perovskite cathode material for IT-SOFC is synthesized successfully using a combustion method and sintered at low temperature. The effects of nickel as a sintering aid on the properties of BaCo0.Fe-4(0).Zr-4(0).O-2(3-delta) are investigated through different characterization methods. The addition of nickel increased the densification and grain growth at a lower sintering temperature 1200 degrees C. XRD analysis confirms a single phase of BaCo0.Fe-4(0).Zr-4(0).O-2(3-delta), and an increase in crystalline size is observed. SEM micrographs show formation of dense microstructure with increased nickel concentration. TGA analysis revealed that BaCo0.Fe-4(0).4Zr0.2-xNix cathode materials are thermally stable within the SOFC temperature range, and negligible weight loss of 2.3% is observed. The bonds of hydroxyl groups and metal oxides are confirmed for all samples through FTIR analysis. The highest electrical properties are observed for BaCo0.Fe-4(0).4Zr0.2-xNix (x = 0.04) due to increased densification and electronic defects compared to other compositions. The maximum power density of 0.47 W cm(-2) is obtained for a cell having cathode material BaCo0.Fe-4(0).4Zr0.2-xNix (x = 0.02) owing to its permeable and well-connected structure compared to others.
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| 2. |
- Manzoor, Numair, et al.
(författare)
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RETRACTED: Experimental Study of CO2 Conversion into Methanol by Synthesized Photocatalyst (ZnFe2O4/TiO2) Using Visible Light as an Energy Source
- 2020
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Ingår i: Catalysts. - : MDPI. - 2073-4344. ; 10:2
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Tidskriftsartikel (refereegranskat)abstract
- Ozone layer depletion is a serious threat due to the extensive release of greenhouse gases. The emission of carbon dioxide (CO2) from fossil fuel combustion is a major reason for global warming. Energy demands and climate change are coupled with each other. CO2is a major gas contributing to global warming; hence, the conversion of CO2 into useful products such as methanol, formic acid, formaldehyde, etc., under visible light is an attractive topic. Challenges associated with the current research include synthesizing a photocatalyst that is driven by visible light with a narrow band gap range between 2.5 and 3.0 eV, the separation of a mixed end product, and the two to three times faster recombination rate of an electron–hole pair compared with separation over yield. The purpose of the current research is to convert CO2 into useful fuel i.e., methanol; the current study focuses on the photocatalytic reduction of CO2into a useful product. This research is based on the profound analysis of published work, which allows the selection of appropriate methods and material for this research. In this study, zinc ferrite (ZnFe2O4) is synthesized via the modified sol–gel method and coupled with titanium dioxide (TiO2). Thereafter, the catalyst is characterized by Fourier transform infrared (FTIR), FE-SEM, UV–Vis, and XRD characterization techniques. UV–Vis illustrates that the synthesized catalyst has a low band gap and utilizes a major portion of visible light irradiation. The XRD pattern was confirmed by the formation of the desired catalyst. FE-SEM illustrated that the size of the catalyst ranges from 50 to 500 nm and BET analysis determined the surface area, which was 2.213 and 6.453 m2/g for ZnFe2O4 and ZnFe2O4/TiO2, respectively. The continuous gas flow photoreactor was used to study the activity of the synthesized catalyst, while titanium dioxide (TiO2) has been coupled with zinc ferrite (ZnFe2O4) under visible light in order to obtain the maximum yield of methanol as a single product and simultaneously avoid the conversion of CO2 into multiple products. The performance of ZnFe2O4/TiO2was mainly assessed through methanol yield with a variable amount of TiO2 over ZnFe2O4 (1:1, 1:2, 2:1, 1:3, and 3:1). The synthesized catalyst recycling ability has been tested up to five cycles. Finally, we concluded that the optimum conditions for maximum yield were found to be a calcination temperature of ZnFe2O4at 900 °C, and optimum yield was at a 1:1 w/w coupling ratio of ZnFe2O4/TiO2. It was observed that due to the enhancement in the electron–hole pair lifetime, the methanol yield at 141.22 μmol/gcat·h over ZnFe2O4/TiO2was found to be 7% higher than the earlier reported data.
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| 3. |
- Akbari, Hesam, et al.
(författare)
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Recognizing seizure using Poincaré plot of EEG signals and graphical features in DWT domain
- 2023
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Ingår i: Bratislava Medical Journal. - : AEPress. - 0006-9248 .- 1336-0345. ; 124:1, s. 12-24
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Tidskriftsartikel (refereegranskat)abstract
- Electroencephalography (EEG) signals are considered one of the oldest techniques for detecting disorders in medical signal processing. However, brain complexity and the non-stationary nature of EEG signals represent a challenge when applying this technique. The current paper proposes new geometrical features for classification of seizure (S) and seizure-free (SF) EEG signals with respect to the Poincaré pattern of discrete wavelet transform (DWT) coefficients. DWT decomposes EEG signal to four levels, and thus Poincaré plot is shown for coefficients. Due to patterns of the Poincaré plot, novel geometrical features are computed from EEG signals. The computed features are involved in standard descriptors of 2-D projection (STD), summation of triangle area using consecutive points (STA), as well as summation of shortest distance from each point relative to the 45-degree line (SSHD), and summation of distance from each point relative to the coordinate center (SDTC). The proposed procedure leads to discriminate features between S and SF EEG signals. Thereafter, a binary particle swarm optimization (BPSO) is developed as an appropriate technique for feature selection. Finally, k-nearest neighbor (KNN) and support vector machine (SVM) classifiers are used for classifying features in S and SF groups. By developing the proposed method, we have archived classification accuracy of 99.3 % with respect to the proposed geometrical features. Accordingly, S and SF EEG signals have been classified. Also, Poincaré plot of SF EEG signals has more regular geometrical shapes as compared to S group. As a final remark, we notice that the Poincaré plot of coefficients in S EEG signals has occupied more space as compared to SF EEG signals (Tab. 3, Fig. 11, Ref. 57).
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| 4. |
- Anwer, Hammad, et al.
(författare)
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Experimental Characterization of Unsharp Qubit Observables and Sequential Measurement Incompatibility via Quantum Random Access Codes
- 2020
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 125:8
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Tidskriftsartikel (refereegranskat)abstract
- Unsharp measurements are increasingly important for foundational insights in quantum theory and quantum information applications. Here, we report an experimental implementation of unsharp qubit measurements in a sequential communication protocol, based on a quantum random access code. The protocol involves three parties; the first party prepares a qubit system, the second party performs operations that return both a classical and quantum outcome, and the latter is measured by the third party. We demonstrate a nearly optimal sequential quantum random access code that outperforms both the best possible classical protocol and any quantum protocol that utilizes only projective measurements. Furthermore, while only assuming that the involved devices operate on qubits and that detected events constitute a fair sample, we demonstrate the noise-robust characterization of unsharp measurements based on the sequential quantum random access code. We apply this characterization towards quantifying the degree of incompatibility of two sequential pairs of quantum measurements.
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| 5. |
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| 6. |
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| 7. |
- Hameed, Zeeshan, et al.
(författare)
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A Comprehensive Review on Thermal Coconversion of Biomass, Sludge, Coal, and Their Blends Using Thermogravimetric Analysis
- 2020
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Ingår i: Journal of Chemistry. - : Hindawi Publishing Corporation. - 2090-9063 .- 2090-9071. ; 2020
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Forskningsöversikt (refereegranskat)abstract
- Lignocellulosic biomass is a vital resource for providing clean future energy with a sustainable environment. Besides lignocellulosic residues, nonlignocellulosic residues such as sewage sludge from industrial and municipal wastes are gained much attention due to its large quantities and ability to produce cheap and clean energy to potentially replace fossil fuels. These cheap and abundantly resources can reduce global warming owing to their less polluting nature. The low-quality biomass and high ash content of sewage sludge-based thermal conversion processes face several disadvantages towards its commercialization. Therefore, it is necessary to utilize these residues in combination with coal for improvement in energy conversion processes. As per author information, no concrete study is available to discuss the synergy and decomposition mechanism of residues blending. The objective of this study is to present the state-of-the-art review based on the thermal coconversion of biomass/sewage sludge, coal/biomass, and coal/sewage sludge blends through thermogravimetric analysis (TGA) to explore the synergistic effects of the composition, thermal conversion, and blending for bioenergy production. This paper will also contribute to detailing the operating conditions (heating rate, temperature, and residence time) of copyrolysis and cocombustion processes, properties, and chemical composition that may affect these processes and will provide a basis to improve the yield of biofuels from biomass/sewage sludge, coal/sewage sludge, and coal/biomass blends in thermal coconversion through thermogravimetric technique. Furthermore, the influencing factors and the possible decomposition mechanism are elaborated and discussed in detail. This study will provide recent development and future prospects for cothermal conversion of biomass, sewage, coal, and their blends.
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| 8. |
- Hameedi, Alley, 1984-, et al.
(författare)
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Experimental quantum solution to the Dining Cryptographers Problem
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Quantum resources such as superposition and entanglement have been used to provide unconditional key distribution, secret sharing and communication complexity reduction. In this letter we present a novel quantum information protocol for dining cryptographers problem and anonymous vote casting by a group of voters. We successfully demonstrate the experimental realization of the protocol using single photon transmission. Our implementation employs a flying particle scheme where a photon passes by the voters who perform a sequence of actions (unitary transformations) on the photonic state at their local stations.
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| 9. |
- Muhammad, Sadiq, et al.
(författare)
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Quantum Bidding in Bridge
- 2014
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Ingår i: Physical Review X. - 2160-3308. ; 4:2
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Tidskriftsartikel (refereegranskat)abstract
- Quantum methods allow us to reduce communication complexity of some computational tasks, with several separated partners, beyond classical constraints. Nevertheless, experimental demonstrations of this have thus far been limited to some abstract problems, far away from real-life tasks. We show here, and demonstrate experimentally, that the power of reduction of communication complexity can be harnessed to gain an advantage in a famous, immensely popular, card game-bridge. The essence of a winning strategy in bridge is efficient communication between the partners. The rules of the game allow only a specific form of communication, of very low complexity (effectively, one has strong limitations on the number of exchanged bits). Surprisingly, our quantum technique does not violate the existing rules of the game (as there is no increase in information flow). We show that our quantum bridge auction corresponds to a biased nonlocal Clauser-Horne-Shimony-Holt game, which is equivalent to a 2 -> 1 quantum random access code. Thus, our experiment is also a realization of such protocols. However, this correspondence is not complete, which enables the bridge players to have efficient strategies regardless of the quality of their detectors.
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| 10. |
- Nawareg, Mohamed, et al.
(författare)
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Experimental Measurement-Device-Independent Entanglement Detection
- 2015
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 5
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Tidskriftsartikel (refereegranskat)abstract
- Entanglement is one of the most puzzling features of quantum theory and of great importance for the new field of quantum information. The determination whether a given state is entangled or not is one of the most challenging open problems of the field. Here we report on the experimental demonstration of measurement-device-independent (MDI) entanglement detection using witness method for general two qubits photon polarization systems. In the MDI settings, there is no requirement to assume perfect implementations or neither to trust the measurement devices. This experimental demonstration can be generalized for the investigation of properties of quantum systems and for the realization of cryptography and communication protocols.
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