Optimizing a Broad Energy High Purity Germanium (BEGe) Detector Operated at Shallow Depth in Abu Dhabi

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

Secondary implementation of interactive engagement teaching techniques: Choices and challenges in a Gulf Arab context

We report on a "Collaborative Workshop Physics" instructional strategy to deliver the first IE calculus-based physics course at Khalifa University, UAE. To these authors' knowledge, this is the first such course on the Arabian Peninsula using PER-based instruction. A brief history 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 US. With these questions in view, a pre-reform baseline of MPEX, FCI, course exam 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 from = 0.16+/-0.10 pre- to = 0.47+/-0.08 post-reform, indicating successful SI. We also find that is strongly modulated by language proficiency and discuss likely causes. Regardless of language skill, problem-solving skill is also improved and course DFW rates drop 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 at odds with the classroom norms of well-functioning PER-based instruction. This result is 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 other institutions, both in the Gulf Region and developing world, facing similar challenges involving SI of PER-based instruction outside the US.Comment: v1: 28 pages, 9 figures. v2: 19 pages, 6 figures, includes major reorganization and revisions based on anonymous peer review. v3: 19 pages, 6 figures, minor revisions based on anonymous peer revie

RAAD: LIGHT-1 CubeSat's Payload for the Detection of Terrestrial Gamma-Ray Flashes

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.Comment: 19 pages, 15 figure

An investigation into the role of school leadership in school improvement, including teachers’ and students’ development: A case study of two Saudi Arabian high schools.

Since Saudi Arabia began enthusiastically developing its position in the world, excellence in education has come to the fore asa key driver to the country‘s growth. However, school improvement has received insufficient attention from educators, policy makers, and scholars. This has resulted in Saudi schools suffering from a dearth of empirical studies designed to explore their needs in terms of the professional development of teachers to benefit students. In response, this study was conducted to fill in the current gap arising from the lack of empirical studies in this particular field, through considering the role of school leadership in school improvement and the associated requirements for the professional development of teachers and students in relation to school improvement.The present study design relied on interpretivist qualitative methods, including documentary analysis, face-to-face semi-structured interviews and group interviews. The participants involved in the study were two school leaders, two school deputies, two student advisors and twelve teachers (face-to-face semi-structured interviews), and four groups of nine students (group interviews). The data was analysed using thematic analysis techniquesfollowing an interpretative coding approach.The findings of the study reveal school leadership plays a significant role in school improvement. This is due to the authority of the school leadership team over essential factors related to the quality of teaching and learning, i.e. leadership style, school culture, inclusion,student voice, individual differences, school curriculum, school-parent relationships, PLCs, teaching effectiveness and class size. The findings also confirm that school improvement is also affected by several external factors; i.e. educational policy, the context of the school, the services available in the school district, society, lifestyle, external relationships, and the media. Although the result of this study is non-generalizable, it can be used to inform practitioners, researchers, and policy makers about how best to ensure school improvement in Saudi Arabia.</div

Colonic Foreign Body Retrieval Using a Modified TAMIS Technique with Standard Instruments and Trocars

Background. Reports of retained colorectal foreign bodies (CFBs) are no longer considered uncommon. We present a case where a retained CFB was retrieved using a modified TAMIS technique using standard instruments and trocars. Case Report. A 52-year-old man presented with a CFB. We report our technique of extraction with standard laparoscopic instruments without specialized access platforms. Conclusions. This modified TAMIS technique is well suited for resource poor environments because it requires no specialized equipment, platforms, or additional skill sets compared to conventional laparoscopy

Preparation and characterization of poly(Bisphenol A-Phthalate) and its metal removal behavior toward Pb(II), Cu(II), and Cd(II) ions

ABSTRACTThe polymer poly(BPA-phthalate) (BPA-PHTH) was synthesized from BPA and phthaloyl dichloride by using interfacial condensation polymerization. The prepared polymer was characterized using (FTIR,1H-NMR, 13C-NMR, DSC, TGA, SEM, and polymer solution viscosity. The characterization by 1H-NMR, 13C-NMR, and FTIR proved the suggested structure. The DSC shows that the polymer is not linear, while the TGA shows that it is thermally stable up to 350°C. SEM showed solid surface filled with pores. The polymer uptake behavior towards Pb(II), Cd(II), and Cu(II) ions was studied by the batch equilibrium technique as a function of pH and contact time. The metal-ion uptake by the polymer reached at pH = 6 a maximum of 92.59, 65.79, and 72.46 for Pb(II), Cd(II), and Cu(II) ions, respectively. The metal ion uptake properties of the polymer show fitting for Langmuir, Freundlich, and (D-R) isotherm equations. The experimental data fit to both the Langmuir and the Freundlich models (R2 > 0.99). Column experiments were used to determine the loading capacity and study the desorption of metal ions. The metal-bound polymer was regenerated by treatment with 0.1 M HNO3 for Pb(II) and Cd(II), while 0.5 M EDTA for Cu(II). Therefore, it may be employed for the removal of heavy metal pollutants in environmental and industrial applications

The liver and Chilaiditi’s syndrome: Significance of hepatic surface grooves

Chilaiditi’s syndrome describes a symptomatic patient with radiographic findings of interposed colon between the diaphragm and right lobe of liver. It may mimic a pneumoperitoneum on plain radiographs. We present a case in which Chilaiditis’ syndrome was entertained, delaying a decision for laparotomy. This case reinforces the diagnostic difficulty associated with Chilaiditi’s syndrome, and it increases awareness of an uncommon variation in the liver surface anatomy