We report on efforts to design the "Collaborative Workshop Physics" (CWP) instructional strategy to deliver the first interactive engagement (IE) physics course at Khalifa University of Science, ...Technology and Research (KU), United Arab Emirates (UAE). To our knowledge, this work reports the first calculus-based, introductory mechanics course on the Arabian Peninsula using physics education research (PER)-based instruction. A brief history and present context of general university and STEM teaching in the UAE is given. We present this secondary implementation (SI) as a case study of a novel context and use it to determine if PER-based instruction can be successfully implemented far from the cultural context of the primary developer and, if so, how might such SIs differ from SIs within the United States (U.S.) in terms of criteria for and risks to their success. With these questions in view, a prereform baseline comprised of Maryland Physics Expectations in Physics survey, Force Concept Inventory (FCI), course exam grades, and English language proficiency data are used to design a hybrid implementation of Cooperative Group Problem Solving. We find that for students with high English proficiency, normalized gain on FCI improves substantially, from (g) = 0.16±0.10 prereform to (g) = 0.47±0.08 in the CWP pilot (standard errors), indicating a successful SI. However, we also find evidence that normalized gains on FCI are strongly modulated by language proficiency and discuss likely causes. Regardless of language ability, problem solving skill is also substantially improved and course drop-fail-withdrawal rates are cut from 50% to 24%. In particular, we find evidence in post reform student interviews that prior classroom experiences, and not broader cultural expectations about education, are the more significant cause of expectations that are at odds with the classroom norms of well-functioning PER-based instruction.We present this result as evidence that PER-based innovations can be implemented across great changes in cultural context, provided that the method is thoughtfully adapted in anticipation of context and culture-specific student expectations. This case study should be valuable for future reforms at KU, the broader Gulf region, and other institutions facing similar challenges involving SI of PER-based instruction outside the U.S.
We present a measurement of the zenith angle distribution, up to θ=75°, of cosmic ray muons performed in Abu Dhabi (United Arab Emirates, 24.54°N, 54.43°E), at sea level, rigidity cutoff ∼14 GV. The ...measurement has been performed by using a muon tracker based on plastic scintillator strips, wavelength shifting fibers and silicon photomultipliers for a total of 200 readout channels arranged in a compact structure. To our knowledge this is the first measurement of this kind in the Arabian gulf area.
•Compact muon tracker consisting of 200 readout channels.•First measurement, in the Arabian gulf area, of cosmic muon flux at sea level.•Zenith angle distribution has been measured in Saadiyat Island, Abu Dhabi, UAE.
We present the performances and characterization of an array made of S13370-3050CN (VUV4 generation) Multi-Pixel Photon Counters manufactured by Hamamatsu and equipped with a low power consumption ...preamplifier operating at liquid xenon temperature (∼175 K). The electronics is designed for the readout of a matrix of maximum dimension of 8×8 individual photosensors and it is based on a single operational amplifier. The detector prototype presented in this paper utilizes the Analog Devices AD8011 current feedback operational amplifier, but other models can be used depending on the application. A biasing correction circuit has been implemented for the gain equalization of photosensors operating at different voltages. The results show single photon detection capability making this device a promising choice for future generation of large scale dark matter detectors based on liquid xenon, such as DARWIN.
Cryogenic electronics for photosensors operating in liquid xenon Arneodo, F.; Benabderrahmane, M.L.; Bruno, G. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
08/2019, Letnik:
936
Journal Article
Recenzirano
We present the performances and characterization of the cryogenic readout for an array made of Hamamatsu S13370-3050CN (VUV4 generation) Multi-Pixel Photon Counters (MPPC) operated at liquid xenon ...conditions. The electronics is designed to readout a maximum 64 individual VUV4 photosensors and it is based on the Analog Devices AD8011 current feedback operational amplifier. The AD8011 has been also selected for the realization of a preamplifier embedded onto a voltage divider base for the operation of Hamamatsu R11410 photomultiplier tubes. Results from the radio-purity screening of the AD8011 are also reported.
In this work we present the characterization of a Broad Energy Germanium (BEGe) type High Purity Germanium (HPGe) detector, with a carbon fiber entrance window thickness of 0.6 mm and an active area ...of 6305 mm2, operated at shallow depth (~ 8m) in Abu Dhabi, UAE. A 1.6 keV Full Width Half Maximum (FWHM) was obtained for the 662 keV peak of 137Cs. A muon veto was applied, reducing the background by 8 % (for energies greater than 100 keV). Flushing the volume around the detector endcap with nitrogen gas, to remove radon and thus its progeny, further reduced the background by ~3 %. A thorough analysis for the shaping filter parameters showed that the detector has better resolution at low rise-time values (2 - 5 us) especially for low energy gamma (<600keV), keeping the flattop value fixed at 1.1 us.
In this study, the biosorption of copper and zinc ions by Chlorella sp. and Chlamydomonas sp. isolated from local environments in Malaysia was investigated in a batch system and by microscopic ...analyses. Under optimal biosorption conditions, the biosorption capacity of Chlorella sp. for copper and zinc ions was 33.4 and 28.5 mg/g, respectively, after 6 hr of biosorption in an immobilised system. Batch experiments showed that the biosorption capacity of algal biomass immobilised in the form of sodium alginate beads was higher than that of the free biomass. Scanning electron microscopy and energy-dispersive X-ray spectroscopy analyses revealed that copper and zinc were mainly sorbed at the cell surface during biosorption. Exposure to 5 mg/L of copper and zinc affected both the chlorophyll content and cell count of the algal cells after the first 12 hr of contact time.
The Rapid Acquisition Atmospheric Detector (RAAD), onboard the LIGHT-1 3U CubeSat, detects photons between hard X-rays and soft gamma-rays, in order to identify and characterize Terrestrial Gamma Ray ...Flashes (TGFs). Three detector configurations are tested, making use of Cerium Bromide and Lanthanum BromoChloride scintillating crystals coupled to photomultiplier tubes or Multi-Pixel Photon Counters, in order to identify the optimal combination for TGF detection. High timing resolution, a short trigger window, and the short decay time of its electronics allow RAAD to perform accurate measurements of prompt, transient events. Here we describe the overview of the detection concept, the development of the front-end acquisition electronics, as well as the ground testing and simulation the payload underwent prior to its launch on December 21st, 2021. We further present an analysis of the detector's in-orbit system behavior and some preliminary results.
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