NHC-Cu Three-Coordinate Complex as a Promising Photocatalyst for Energy and Electron Transfer Reactions.

Herein, we describe a simple three-coordinate complex of Cu(I) with an NHC and 1,10-phenanthroline ligands as an effective photocatalyst for energy (e.g., olefin E/Z isomerization) and electron transfer (e.g., aryl halide dehalogenation) reactions under blue-light irradiation. This complex can be obtained in a one-pot procedure starting from commercially available reagents and green solvents (EtOH, water). We hereby present a study of its activity and mechanistic insight into its mode of operation.

New realities for Polish primary school informatics education affected by COVID-19.

In the paper, the authors discuss the first research effort to explore the transition from traditional teaching into distance teaching in Polish primary schools enforced by COVID-19. The first research question was addressed to primary school students and was dedicated to furnishing them with ICT equipment for crisis-prompted distance informatics learning. According to the obtained results, almost all Polish students during the pandemic have a technical opportunity to participate in distance learning and to use digital devices to develop their digital competences. Hence the second research question was addressed to the experts, demystifies whether the accessibility and the availability of ICTs could increase students' informatics learning outcomes in out-of-school primary education settings. The obtained results reveal the significant importance of out-of-school informatics education in pandemic time. Moreover, in the first wave of pandemic, distance informatics education had the same or similar effect as if students learn informatics by themselves, without school lessons and teachers' support. The obtained results should strengthen teachers and school leaders in making informed decisions during the shift into distance informatics education. Also, by investigating participants' informatics learning outcomes and teacher preparedness and choices when implementing distance education, authors hope that the study may be helpful for policy-makers with the progressive changes in education and government support for informatics, especially in Poland, in making informed decisions to aid the transition into distance education as well as developing preparedness plans for future pandemics.

The Comparative Estimation of Primary Students' Programming Outcomes Based on Traditional and Distance Out-of-School Extracurricular Informatics Education in Electronics Courses during the Challenging COVID-19 Period.

The authors decided to investigate the impact of the lockdown period and the resulting limitations in informatics education, especially programming, in out-of-school electronics courses using traditional and distance learning modes in primary school COVID-19 pandemic settings. Two extracurricular courses were held successively; the first electronics course was performed in a traditional out-of-school learning mode using Arduino kits, while the other was held using the TinkerCad circuits virtual environment in distance learning mode. A structured questionnaire was administered to students to map their knowledge of programming. The questionnaire consists of three emotional dimensions: enjoyment, satisfaction and motivation. The fourth dimension was dedicated to the students' programming outcomes. Three emotional dimensions were addressed to primary school students, while the fourth dimension was addressed to the tutors' observations toward the students' programming outcomes. The obtained results revealed that learning modes have no significant impact on students perceiving the programming issues. However, three emotional dimensions revealed a significant difference in the students' enjoyment, satisfaction and motivation in favor of the traditional learning mode. Our findings are of particular interest in light of possible crisis-prompted distance education in the future but can also serve to inform government institutions and policymakers seeking to develop effective concepts for successful distance learning.

Interactive Timeline Approach for Contextual Spatio-Temporal ECT Data Investigation.

This paper presents a novel approach to a complex process of electrical capacitance tomography (ECT) measurement data analysis. ECT is frequently employed for non-invasive monitoring of industrial process phenomena. Proposed methodology is based on the premeditated integration of the spatial and temporal relations inherent in the measurement records into the workflow of the analysis procedure. We propose a concept of interactive timeline that enables arranging data visualization according to the user's current focus along the process of analysis. We evaluated the proposed method using a prototype system in a task-based user study conducted with a group of domain experts. The evaluation is based on gravitational silo flow measurement datasets. Proposed prototype system enables diverse data manipulation in a more natural way allowing the user to switch back and forth between space and time domains along the data analysis trail. Experiments with the prototype system showed that the accuracy and completion times have significantly improved in comparison to the performance measured in the baseline condition. Additionally, the participants reported decreased physical load with improved efficiency measured with NASA task load index. Finally, a short discussion coupled with directions for the future of interactive spatio-temporal ECT measurement data analysis conclude the paper.

X-ray Imaging Analysis of Silo Flow Parameters Based on Trace Particles Using Targeted Crowdsourcing.

This paper presents a novel method for tomographic measurement and data analysis based on crowdsourcing. X-ray radiography imaging was initially applied to determine silo flow parameters. We used traced particles immersed in the bulk to investigate gravitational silo flow. The reconstructed images were not perfect, due to inhomogeneous silo filling and nonlinear attenuation of the X-rays on the way to the detector. Automatic processing of such data is not feasible. Therefore, we used crowdsourcing for human-driven annotation of the trace particles. As we aimed to extract meaningful flow parameters, we developed a modified crowdsourcing annotation method, focusing on selected important areas of the silo pictures only. We call this method "targeted crowdsourcing", and it enables more efficient crowd work, as it is focused on the most important areas of the image that allow determination of the flow parameters. The results show that it is possible to analyze volumetric material structure movement based on 2D radiography data showing the location and movement of tiny metal trace particles. A quantitative description of the flow obtained from the horizontal and vertical velocity components was derived for different parts of the model silo volume. Targeting the attention of crowd workers towards either a specific zone or a particular particle speeds up the pre-processing stage while preserving the same quality of the output, quantified by important flow parameters.

Gold(I)-Catalyzed Formation of Naphthalene/Acenaphthene Heterocyclic Acetals.

A gold-catalyzed addition/cyclization reaction to form 3-alkoxy-benzo[de]isochromene derivatives was developed. All reactions, performed in mild conditions, exhibited high regioselectivity and good to excellent reaction yields. Additionally, optimized methodology was used in total synthesis of 2-phenylphenalenone, an alleged natural product found in Macropidia fuliginosa plant.

Mechanistic studies of Hoveyda-Grubbs metathesis catalysts bearing S-, Br-, I-, and N-coordinating naphthalene ligands.

Derivatives of the Hoveyda-Grubbs complex bearing S-, Br-, I-, and N-coordinating naphthalene ligands were synthesized and characterized with NMR and X-ray studies. Depending on the arrangement of the coordinating sites on the naphthalene core, the isomeric catalysts differ in activity in model metathesis reactions. In particular, complexes with the RuCH bond adjacent to the second aromatic ring of the ligand suffer from difficulties experienced on their preparation and initiation. The behavior most probably derives from steric hindrance around the double bond and repulsive intraligand interactions, which result in abnormal chemical shifts of benzylidene protons observed with (1) H NMR. Furthermore EXSY studies revealed that the halogen-chelated ruthenium complexes display an equilibrium, in which major cis-Cl2 structures are accompanied with small amounts of isomeric forms. In general, contents of the minor forms, measured at 80 °C, correlate with the observed activity trends of the catalysts, although some exceptions complicate the mechanistic picture. We assume that for the family of halogen-chelated metathesis catalysts the initiation mechanism starts with the cis-Cl2 ⇌trans-Cl2 isomerization, although further steps may become rate-limiting for selected systems.