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- Aamodt, K., et al.
(författare)
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Alignment of the ALICE Inner Tracking System with cosmic-ray tracks
- 2010
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Ingår i: Journal of Instrumentation. - 1748-0221. ; 5
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Konferensbidrag (refereegranskat)abstract
- ALICE (A Large Ion Collider Experiment) is the LHC (Large Hadron Collider) experiment devoted to investigating the strongly interacting matter created in nucleus-nucleus collisions at the LHC energies. The ALICE ITS, Inner Tracking System, consists of six cylindrical layers of silicon detectors with three different technologies; in the outward direction: two layers of pixel detectors, two layers each of drift, and strip detectors. The number of parameters to be determined in the spatial alignment of the 2198 sensor modules of the ITS is about 13,000. The target alignment precision is well below 10 mu m in some cases (pixels). The sources of alignment information include survey measurements, and the reconstructed tracks from cosmic rays and from proton-proton collisions. The main track-based alignment method uses the Millepede global approach. An iterative local method was developed and used as well. We present the results obtained for the ITS alignment using about 10(5) charged tracks from cosmic rays that have been collected during summer 2008, with the ALICE solenoidal magnet switched off.
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| 5. |
- 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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| 7. |
- 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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| 8. |
- 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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| 10. |
- Jeworrek, A., et al.
(författare)
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Reduction of low arsenic concentrations in drinking water to below 1 µg L−1 by adsorption onto granular iron (Hydr)oxides
- 2018
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Ingår i: Environmental Arsenic in a ChangingWorld - 7th International Congress and Exhibition Arsenic in the Environment, 2018. - London : CRC Press/Balkema. - 9781138486096 ; , s. 593-594
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Konferensbidrag (refereegranskat)abstract
- Arsenic in drinking water should be reduced as much as possible, because it is amongst carcinogenic substances. FerroSorp® Plus, Huijbergen and Spannenburg GIH could reduce As(V) levels in Ouddorp water below the desired 1 µg L−1. Particularly Huijbergen GIH had according to non-linear Freundlich modeling the higher KF value, translating into a potentially higher effective adsorption capacity. One of the characteristics that probably determines the success of a GIH is its physical properties. Since the effective adsorption capacity increases with higher initial As(V) concentrations, Huijbergen GIH is a promising adsorbent to reduce a wide range of arsenic concentrations from drinking water. Therefore, this affordable technology is not only reducing ultra-low arsenic concentrations to even lower concentrations in Ouddorp water but is also promising for developing countries that are seriously affected by high concentrations of arsenic in their drinking water.
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