Monitoring LSO/LYSO Crystal Based Calorimeters

Precision light monitoring is important for keeping excellent energy resolution promised by LSO/LYSO crystals in severe radiation environment. In this paper, we report an investigation on the wavelength choice for monitoring LYSO crystal based calorimeters. Gamma-ray induced absorption and light output loss were measured for 20 cm long crystals from five different vendors. Monitoring sensitivity and divergence between crystals from different vendors were investigated. The pros and cons of two monitoring approaches using emission and excitation light and their practical implementation for a LYSO/W Shashlik test beam matrix are discussed

Encouraging engineering students' participation in face-to-face peer learning

CONTEXT: It is widely accepted that graduate engineers should be equipped with a range of interpersonal skills to be effective team-players in the workforce (Nguyen, 1998). Study Group sessions constitute a platform for students to practice cooperation with peers in a unique learning environment. Specifically, students learn by experience how to collaborate within a diverse group, which helps preparing them for a diverse workforce. Additionally, Study Groups provide real-life support networks beyond the internet domain (Kim, LaRose, and Peng, 2009). However, attracting many students with a variety of backgrounds to attend Study Group sessions is challenging. PURPOSE: This study aims to find effective strategies to attract large numbers of students with a variety of backgrounds and academic performances to participate (in-person) and actively engage in weekly Study Group sessions. The sought strategies do not involve direct academic performance incentives. APPROACH: The Study Group Project (SGP) is an initiative of setting weekly meeting sessions for a variety of subjects (15 subjects in Semester 1, 2018). These sessions, during which students are given a subject-related learning activity to attempt collaboratively without (or, almost without) staff support, are not assessed (thus, attendance is voluntary). In each SGP-hosting subject, a different implementation strategy is used to recruit students. Data on the number of participants and their profiles is collected. End-of-semester surveys are issued to further improve the SGP. RESULTS: Many factors affect Study Group attendance rates. These can be very significant, as can be witnessed from the cumulative attendance rates in Study Group sessions (during a semester) ranging from less than 2% (of number of enrolled students in the subject) in some subjects to more than 80% in others. Low attendance rates correlated with inappropriate levels of the learning activities (either too difficult or too easy), timetable clashes, and insufficient promotion on the Learning Management System (LMS). While some initial assistance by a tutor and supplying answers in the following session have contributed to attendance rates, these were not essential. In contrast, consistency of implementing Study Group sessions across semesters proved very beneficial. CONCLUSIONS: Our project highlights some communication challenges faced by engineering students (resulting in diminished collaboration skills), their reliance on having correct final answers and/or authorised support person available, and their prioritisation of learning outcomes that are formally assessed (thus neglecting important skills for their future career). We hope to disseminate the idea of holding Study Groups, where students work collaboratively in a diverse environment that somewhat imitates a workplace. We provide practical implementation strategies to help found similar initiatives

UV–Visible reflectance of common light reflectors and their degradation after an ionization dose up to 100 Mrad

Light reflectors are widely used to enhance scintillation light collection. Their enhancement level depends on the reflector’s reflectance at the scintillator’s emission wavelength. We report UV–Visible reflectance spectra, relative to BaSO₄, for several common reflectors. Also reported is their radiation hardness against an ionization dose up to 100 Mrad. The results of this investigation provide a reference for applications of these reflectors in a severe radiation environment

(E)-2-Meth­oxy-6-(thia­zol-2-ylimino­meth­yl)phenol

The title compound, C11H10N2O2S, displays an E configuration about the C=N bond. The mean planes of the thia­zole and benzene rings make a dihedral angle of 9.32 (18)°. Intra­molecular O—H⋯N hydrogen bonds are found in the crystal structure

3,3′-Oxybi[isobenzofuran-1(3H)-one]

The title compound, C16H10O5, consists of two isobenzofuran-1(3H)-one moieties which are linked by a bridging O atom. The two halves of the mol­ecule display approximate non-crystallographic mirror symmetry. The dihedral angle between the two isobenzofuran-1(3H)-one ring systems is 53.18 (6) Å. Two chiral carbon centres are observed in the compound, but their absolute configurations could not be determined. In the crystal structure, inter­molecular C—H⋯O hydrogen bonds link mol­ecules into zigzag chains along c. Additional C—H⋯O inter­actions connect adjacent chains

3-[(3-Oxo-1,3-dihydro­isobenzofuran-1-yl)amino]benzoic acid

In the title compound, C15H11NO4, the dihedral angle formed by the benzene ring and isobenzofuran ring system is 67.82 (5) Å. The crystal structure is stabilized by inter­molecular O—H⋯O and N—H⋯O hydrogen-bonding inter­actions

Octa­butyl­bis{(E)-2-[4-(2-hydroxy­benzyl­ideneamino)phen­yl]acetato}di-μ2-methoxo-di-μ3-oxido-tetra­tin(IV)

The title compound, [Sn4(C4H9)8(C15H12NO3)2(CH3O)2O2], is a centrosymmetric dimer and displays a ladder type structural motif. There are four SnIV centres which can be divided into two sorts, viz. two endocyclic and two exocyclic. The endo- and exocyclic SnIV centres are linked by bidentate deprotonated methanol and μ3-O atoms. Each exocyclic SnIV centre is also coordinated by a monodentate 2-[4-(2-hydroxy­benzyl­idene­amino)phen­yl]acetate ligand. Parts of the butyl groups were found to be disordered over two sets of sites

Surface-neutralization engineered NiCo-LDH/phosphate hetero-sheets toward robust oxygen evolution reaction

Developing highly active oxygen evolution reaction (OER) electrocatalysts with robust durability is essential in producing high-purity hydrogen through water electrolysis. Layered double hydroxide (LDH) based catalysts have demonstrated efficient catalytic performance toward the relatively sluggish OER. By considering the promotion effect of phosphate (Pi) on proton transfer, herein, a facile phosphate acid (PA) surface-neutralization strategy is developed to in-situ construct NiCo-LDH/NiCoPi hetero-sheets toward OER catalysis. OER activity of NiCo-LDH is significantly boosted due to the proton promotion effect and the electronic modulation effect of NiCoPi. As a result, the facilely prepared NiCo-LDH/NiCoPi catalyst displays superior OER catalytic activity with a low overpotential of 300 mV to deliver 100 mA cm−2 OER and a Tafel slope of 73 mV dec−1. Furthermore, no visible activity decay is detected after a 200-h continuous OER operation. The present work, therefore, provides a promising strategy to exploit robust OER electrocatalysts for commercial water electrolysers

Methane steam reforming reaction in solid oxide fuel cells:Influence of electrochemical reaction and anode thickness

The influence of operation temperature, inlet gas composition, current density and the anode thickness on the methane steam reforming reaction over nickel yttria-stabilized zirconia anodes was experimentally studied in solid oxide fuel cells. The experimental results were analyzed using data fitting in Power-Law and Langmuir–Hinshelwood kinetic models. Similar trends of dependence of methane and steam partial pressures were observed in both models. The methane reaction order is positive. Negative influence of steam partial pressure on the methane steam reforming reaction rate are found. The electrochemical reaction and anode thickness affect the reforming kinetics parameters. The anodes thickness shows particular influences on the steam reaction order, and the activation energy when a current is produced. The model evaluation suggests that the two models are comparable and the extra parameters within the Langmuir–Hinshelwood kinetic model are contributing to the lower mean absolute percentage error and higher coefficient of determination