| 1. |
- Ahmed, A., et al.
(författare)
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Highly efficient composite electrolyte for natural gas fed fuel cell
- 2016
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Ingår i: International journal of hydrogen energy. - : Elsevier. - 0360-3199 .- 1879-3487. ; 41:16, s. 6972-6979
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Tidskriftsartikel (refereegranskat)abstract
- Solid oxide fuel cells (SOFCs) have the ability to operate with different variants of hydro carbon fuel such as biogas, natural gas, methane, ethane, syngas, methanol, ethanol, hydrogen and any other hydrogen rich gas. Utilization of these fuels in SOFC, especially the natural gas, would significantly reduce operating cost and would enhance the viability for commercialization of FC technology. In this paper, the performance of two indigenously manufactured nanocomposite electrolytes; barium and samarium doped ceria (BSDC-carbonate); and lanthanum and samarium doped ceria (co-precipitation method LSDC-carbonate) using natural gas as fuel is discussed. The nanocomposite electrolytes were synthesized using co-precipitation and wet chemical methods (here after referred to as nano electrolytes). The structure and morphology of the nano electrolytes were examined by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The fuel cell performance (OCV) was tested at temperature (300-600 °C). The ionic conductivity of the nano electrolytes were measured by two probe DC method. The detailed composition analysis of nano electrolytes was performed with the help of Raman Spectroscopy. Electrochemical study has shown an ionic conductivity of 0.16 Scm-1 at 600 °C for BSDC-carbonate in hydrogen atmosphere, which is higher than conventional electrolytes SDC and GDC under same conditions. In this article reasonably good ionic conductivity of BSDC-carbonate, at 600 °C, has also been achieved in air atmosphere which is comparatively greater than the conventional SDC and GDC electrolytes.
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| 2. |
- Kumar, M., et al.
(författare)
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Frontier review on the propensity and repercussion of SARS-CoV-2 migration to aquatic environment
- 2020
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Ingår i: Journal of Hazardous Materials Letters. - : Elsevier BV. - 2666-9110. ; 1
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Tidskriftsartikel (refereegranskat)abstract
- Increased concern has recently emerged pertaining to the occurrence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in aquatic environment during the current coronavirus disease 2019 (COVID-19) pandemic. While infectious SARS-CoV-2 has yet to be identified in the aquatic environment, the virus potentially enters the wastewater stream from patient excretions and a precautionary approach dictates evaluating transmission pathways to ensure public health and safety. Although enveloped viruses have presumed low persistence in water and are generally susceptible to inactivation by environmental stressors, previously identified enveloped viruses persist in the aqueous environment from days to several weeks. Our analysis suggests that not only the surface water, but also groundwater, represent SARS-CoV-2 control points through possible leaching and infiltrations of effluents from health care facilities, sewage, and drainage water. Most fecally transmitted viruses are highly persistent in the aquatic environment, and therefore, the persistence of SARS-CoV-2 in water is essential to inform its fate in water, wastewater and groundwater and subsequent human exposure.
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| 3. |
- Baharin, S. A. S., et al.
(författare)
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Wavelet Analysis of the Onset of VHF and Microwave Radiation Emitted by Lightning
- 2018
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Ingår i: 2018 INTERNATIONAL CONFERENCE ON ELECTRICAL ENGINEERING AND COMPUTER SCIENCE (ICECOS). - : IEEE. - 9781538657218 ; , s. 297-300
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Konferensbidrag (refereegranskat)abstract
- Lightning flash is an electrical discharge in air (dielectric breakdown) which emits electromagnetic (FM) fields across very wide spectra from a few Hertz up to visible wavelength. Electrical breakdown process is an important event that initiates lightning. For electrical breakdown process to occur, it must fulfill two conditions which are at least has one free electron and the electric field region is more than 3 MV/m. This process starts with electron avalanche in millimeter scale then grows into streamer in centimeter scale. Lastly, from streamer it will grow into leader in meter scale. It has already established that streamer emits intensely at Very High Frequency (VHF) band as it's already proven both theoretically and experimentally. A study by Cooray, theoretically proved that emission of electron avalanche peaks at microwave band. Air-gap parallel plate antenna which could operate at 1 GHz with remote sensing is designed and simulated to measure the microwave radiation emitted by lightning. Both temporal and wavelet analyses are used to compare the onset of microwave radiation and VHF radiation in both time and frequency domains to determine electron avalanche appears at which electromagnetic band.
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| 4. |
- Kanwal, Ansa, et al.
(författare)
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Polyethersulfone (PES) nanofiltration membrane for treatment of toxic metal contaminated water
- 2022
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Ingår i: Emerging Techniques for Treatment of Toxic Metals from Wastewater. - 9780128228807 ; , s. 319-341
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Polyethersulfone is most extensively utilized material in waste treatment application via membranes technology since it offers high thermal, chemical, and mechanical properties. The world now has problems with drinking water and the present situation seems to be very complex to meet clean water requirements. The treatment of water supplies by clean-up techniques is urgently considered by increased daily demand, which leads to dangerous conditions unless this problem is controlled. Most important contributors to ecological pollution with metal ions are mining, metal shining, power generation houses, galvanization, tannery industries, metallurgical, and electroplating. There are many techniques to remove the metal ions such as adsorption, microbial fuel cells, oxidation/reductions, ion exchange etc. Among all the technologies nanofiltration membranes attract more attention to remove the toxic metal ions from water even at lower concentration. It is very simple, feasible and economically affordable technology. Several types of nanofiltration techniques are used before but most attractive is polyethersulfone (PES) nanofiltration membrane. It minimizes several issues which are present in the nanofiltration process. In this chapter we briefly discussed the modification strategies and removal efficiency of metal ions via polyethersulfone (PES) nanofiltration membrane.
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| 5. |
- Seah, B. Y., et al.
(författare)
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Narrow Bipolar Events within Reversal Distance and Associated UHF-VHF Emissions
- 2019
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Ingår i: 2019 3RD INTERNATIONAL CONFERENCE ON ELECTRICAL ENGINEERING AND COMPUTER SCIENCE (ICECOS 2019). - : IEEE. - 9781728147147 ; , s. 132-136
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Konferensbidrag (refereegranskat)abstract
- This paper investigates the characteristics of the ultra-high frequency (UHF) and Very High Frequency (VHF) emissions that associate with negative narrow bipolar events (NBEs) which occurred within reversal distance, drev of the base station. The UHF emissions were captured by using a parallel plates antenna with its center frequency at 0.97 GHz and 20 MHz bandwidth. There are thirteen samples whereby their VHF and FF signals were leaded by their corresponding UHF about (102.25 +/- 125.48) ns and (692.13 +/- 382.36) ns respectively. All the UHF were found to behave like continuous bursting while some of the VHF consisted of certain periods within its burst train whereby there was no any sign of pulse during that period.
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| 6. |
- Seah, B. Y., et al.
(författare)
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The Performance Evaluation of Capacitive Antenna with Various Structures and Permittivity Values
- 2018
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Ingår i: 2018 INTERNATIONAL CONFERENCE ON ELECTRICAL ENGINEERING AND COMPUTER SCIENCE (ICECOS). - : IEEE. - 9781538657218 ; , s. 457-460
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Konferensbidrag (refereegranskat)abstract
- This paper evaluates the capacitive antenna performance as a lightning sensor. The performance is evaluated by looking at two aspects, antenna structures and the background permittivity value of the antenna. Two experiments were carried out, Experiment A using two different structure antennas, one with its Bayonet Neill-Concelman (BNC) connector's core direct touching the top plate (DBNC) while the other was connected via single core wires (WBNC), capturing the electric field (E-field) generated by the small spark at a distance of 1 meter away from both antennas. Furthermore, both capacitive antennas with top plates directly soldered to their BNC cores were used to study their performance with and without being covered by plastic (dielectric constant of 2.25) during Experiment B. The result from Experiment A showed that WBNC has different onset polarity and significant decreased in amplitude of the signals captured compared to DBNC (mean ratio is 1.095 with range between 0.5838 and 4.528). Meanwhile, Experiment B shows that a comparable average ratio of 0.7835 and 0.7447 during the measurement where antenna A(wc) with and without the presence of plastic cover respectively.
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| 7. |
- Eddine Lamri, I., et al.
(författare)
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Design and development of a graphene-based reconfigurable patch antenna array for THz applications
- 2023
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Ingår i: Frequenz. - : Walter de Gruyter GmbH. - 0016-1136 .- 2191-6349. ; 77:3-4, s. 219-228
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents a graphene-based antenna array for terahertz (THz) applications. The suggested antenna array has four radiating square shaped patches fed by a coplanar waveguide (CPW) technique. The proposed antenna array operates at the three frequencies with operational bandwidths of 1.173-1.210 THz (at 1.19 THz), 1.270-1.320 THz (at 1.3 GHz), and 1.368-1.346 THz (at 1.4 GHz). The total area of the antenna array is reported as 1000 × 1000 μm2, printed on a Silicon substrate with a thickness of 20 μm and a dielectric constant of ϵ r = 11.9. To enhance the structure's performance and optimize the feeding network, a parametric analysis was performed using the FDTD technique. Furthermore, the key properties of the proposed antenna array, such as resonance frequency, peak gain, and radiation efficiency, may be changed by adjusting the chemical potentials of the graphene in the antenna array. The use of graphene's chemical potential tuneability yields exceptional results comparing to the recent research outputs, with a peak gain and radiation efficiency of 10.45 dB and 70%, respectively. These results show the performance of the suggested design for constructing antenna arrays for use in THz applications.
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| 8. |
- Hussain, F., et al.
(författare)
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Electrochemical investigation of multi-fuel based low temperature nano-composite anode for solid oxide fuel cell
- 2019
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Ingår i: Journal of Power Sources. - : Elsevier B.V.. - 0378-7753 .- 1873-2755. ; 425, s. 147-152
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Tidskriftsartikel (refereegranskat)abstract
- Extensive efforts have been made in order to develop multi-fuel-based low temperature solid oxide fuel cell for direct conversion of hydrocarbons to electric power. It is extremely difficult to operate due to the C–H activation and its tremendously sluggish oxidation reduction in the low temperature range from 300 to 600 °C. The structural and electrochemical properties of novel anode material Ni 0.6 (Ba 0.3 Ce 0.2 Zn 0.5 ) 0.4 have been investigated in the presence of hydrogen, natural gas, ethanol, glucose, and sugar-cane at low temperature of 600 °C. Through sol-gel method the proposed oxide material is synthesized. The composite average crystalline size has been found 25–90 nm by both scanning electron microscopy and X-ray diffraction techniques. The ultraviolet– visible and Fourier transform infrared techniques are used to determine band gap and absorption spectrum respectively. The power density of the cell at various fuels has been observed and measurements indicate that it varies from 57 to 315 mWcm −2 at 600 °C among different fuels at anode side. The current study reveals that proposed anode Ni 0.6 (Ba 0.3 Ce 0.2 Zn 0.5 ) 0.4 is promising multi-fuel anode material for low-temperature solid oxide fuel cell, and it does not need to reform hydrocarbon fuels in order to fully utilize the advantage of these cells.
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| 9. |
- Ong, J. Y., et al.
(författare)
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Performance Analysis of Stacked Capacitive Antenna for Lightning Remote Sensing
- 2018
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Ingår i: 2018 INTERNATIONAL CONFERENCE ON ELECTRICAL ENGINEERING AND COMPUTER SCIENCE (ICECOS). - : IEEE. - 9781538657218 ; , s. 305-308
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Konferensbidrag (refereegranskat)abstract
- Antennas are the important elements in the lightning detection system. To improve performance of the lightning detection system, it is so necessary to improve the efficiency of the antennas. There are two types of antennas used in the system which are capacitive antenna for electric field sensing and loop antenna for magnetic field sensing Pi. Both of these antennas arc big in size and causing inconvenient during set up. Thus, small and portable antennas are designed. It is so important to remain or improve the sensitivity of the antennas even though it is small in size. Stacking method is used in capacitive antenna by increase copper plate layer in between the parallel plate antenna. After prototype the multi stacked capacitive antenna, performance analysis is carried out. Performances of the antennas are compared using CST simulation and hardware set up. Multi-stacked capacitive antenna is compared with the single plate antenna and found that the performance of the antenna increases as the stacked number increases.
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| 10. |
- Rafique, Asia, et al.
(författare)
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Design and Modeling of a Fuel Cell System Using Biomass Feedstock as a Biofuel
- 2020
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Ingår i: Fuel Cells. - : Wiley. - 1615-6846 .- 1615-6854. ; 20:1, s. 89-97
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Tidskriftsartikel (refereegranskat)abstract
- This paper aims to model ceramic fuel cell system based on low-temperature planar solid oxide fuel cell (SOFC) different biogases fuels from multiple biomasses, that is, animal waste, redwood, rice husk and sugar cane. Biomass is a better choice for the generation of energy globally. Therefore, there is a focus on the most available biomass resources in the country that can be used as clean energy sources. This developed model is designed by thermodynamic analysis and electrochemical calculations using MATLAB. The designed model is a lumped parameter model based on the steady-state one-dimensional flow. In this model, all calculated power and flow rate values were kept as positive values. Also, the system is considered to be free of leaks, and heat loss is neglected. The operating temperature and pressure are assumed to be 500–700 °C and the partial pressure is set at three different pressures; P1 (1 bar), P2 (2 bar), and P3 (3 bar), respectively, and fuel utilization factor is 80%. It is observed that the best performance is obtained with animal-waste based biogas at 700 °C and P3 (3 bar).
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