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Interactive textbooks generate big data through student reading participation, including animations, question sets, and auto-graded homework. Animations are multi-step, dynamic visuals with text captions. By dividing new content into smaller chunks of information, student engagement is expected to be high, which aligns with tenets of cognitive load theory. Specifically, students’ clicks are recorded and measure usage, completion, and view time per step and for entire animations. Animation usage data from an interactive textbook for a chemical engineering course in Material and Energy Balances accounts for 60,000 animation views across 140+ unique animations. Data collected across five cohorts between 2016 and 2020 used various metrics to capture animation usage including watch and re-watch rates as well as the length of animation views. Variations in view rate and time were examined across content, parsed by book chapter, and five animation characterizations (Concept, Derivation, Figures and Plots, Physical World, and Spreadsheets). Important findings include: 1) Animation views were at or above 100% for all chapters and cohorts, 2) Median view time varies from 22 s (2-step) to 59 s (6-step) - a reasonable attention span for students and cognitive load, 3) Median view time for animations characterized as Derivation was the longest (40 s) compared to Physical World animations, which resulted in the shortest time (20 s). 

Faculty often utilize homework problems as a means to help students practice problem solving. Recently, with textbook solutions manuals being freely available online, students are prone to copying/cheating, which can severely limit improvements in problem solving. One hypothesis is that YouTube problems could serve as alternatives to textbook problems to significantly reduce cheating and promote better problem solving. YouTube problems are student-written problems that were inspired by events in a video publicly available online. While our previous studies have showcased positive attitudes related to engineering, high engagement, and rigor of the YouTube problems, the current study examines a subset of problems related to one major course topic, namely vapor-liquid equilibrium. The cohorts include engineering students from a public university who were assigned homework problems as part of a material and energy balance course. Two constructs were explored: problem solving and perception of problem difficulty. The study adopted an established and validated rubric to quantify performance in relevant stages of problem solving, including problem identification, representation, organization, calculation, solution completion, and solution accuracy. While problem solving can be influenced by perception of problem difficulty, the widely used NASA Task Load Index was adopted to measure the problem rigor. This paper will compare textbook and YouTube problem with respect to overall problem-solving ability as well as in each stage of problem solving. Furthermore, we will investigate whether disparities exist in students’ perceptions when solving vapor-liquid equilibrium problems. 

Complex problem-solving is a vital skill prevalent to thrive in the workforce along with creativity and conceptual thinking. Homework problems allow engineering students to practice problem solving, and writing new problems can be a creative process for students. Our previous research found that implementing alternative, student-written homework problems, referred to as YouTube problems, led to better learning attitudes. YouTube problems are course related; homework-quality problems generated by reverse engineering publicly available videos. Comparing learning experiences of students solving YouTube versus Textbook problems is the focus of the current study. Impacts of solving YouTube problems are examined based on perception of difficulty as well as students’ problem-solving skills displayed by students. To enable testing, students were assigned one textbook and three YouTube problems. Perception of problem difficulty across problems was examined using the NASA Task Load Index. Additionally, problem solving aptitudes while solving homework problems was assessed using a previously validated rubric called PROCESS: Problem definition, Representing the problem, Organizing the information, Calculations, Solution completion, and Solution accuracy. A new case study compares Textbook and YouTube problems related to reacting systems with recycle, which is one of the most difficult course concepts. A correlation between problem rigor and problem solving was found. 

A search for pair production of squarks or gluinos decaying via sleptons or weak bosons is reported. The search targets a final state with exactly two leptons with same-sign electric charge or at least three leptons without any charge requirement. The analysed data set corresponds to an integrated luminosity of 139 fb⁻¹of proton-proton collisions collected at a centre-of-mass energy of 13 TeV with the ATLAS detector at the LHC. Multiple signal regions are defined, targeting several SUSY simplified models yielding the desired final states. A single control region is used to constrain the normalisation of theWZ+ jets background. No significant excess of events over the Standard Model expectation is observed. The results are interpreted in the context of several supersymmetric models featuring R-parity conservation or R-parity violation, yielding exclusion limits surpassing those from previous searches. In models considering gluino (squark) pair production, gluino (squark) masses up to 2.2 (1.7) TeV are excluded at 95% confidence level.

 

A search for supersymmetry targeting the direct production of winos and higgsinos is conducted in final states with either two leptons (eorμ) with the same electric charge, or three leptons. The analysis uses 139 fb⁻¹ofppcollision data at$$ \sqrt{s} $$$\sqrt{s}$= 13 TeV collected with the ATLAS detector during Run 2 of the Large Hadron Collider. No significant excess over the Standard Model expectation is observed. Simplified and complete models with and withoutR-parity conservation are considered. In topologies with intermediate states including eitherWhorWZpairs, wino masses up to 525 GeV and 250 GeV are excluded, respectively, for a bino of vanishing mass. Higgsino masses smaller than 440 GeV are excluded in a naturalR-parity-violating model with bilinear terms. Upper limits on the production cross section of generic events beyond the Standard Model as low as 40 ab are obtained in signal regions optimised for these models and also for anR-parity-violating scenario with baryon-number-violating higgsino decays into top quarks and jets. The analysis significantly improves sensitivity to supersymmetric models and other processes beyond the Standard Model that may contribute to the considered final states.

 

Search for a new pseudoscalar a-boson decaying to muons in events with additional top quark pairs. 

A search for dark matter produced in association with a Higgs boson in final states with two hadronically decayingτ-leptons and missing transverse momentum is presented. The analysis uses 139 fb⁻¹of proton-proton collision data at$$ \sqrt{s} $$$\sqrt{s}$= 13 TeV collected by the ATLAS experiment at the Large Hadron Collider between 2015 and 2018. No evidence of physics beyond the Standard Model is found. The results are interpreted in terms of a 2HDM+amodel featuring two scalar Higgs doublets and a pseudoscalar singlet field. Exclusion limits on the parameters of the model in selected benchmark scenarios are derived at 95% confidence level. Model-independent limits are also set on the visible cross-section for processes beyond the Standard Model producing missing transverse momentum in association with a Higgs boson decaying intoτ-leptons.

 

A search for pair-produced vector-like quarks using events with exactly one lepton (eor$$\mu $$$\mu$), at least four jets including at least oneb-tagged jet, and large missing transverse momentum is presented. Data from proton–proton collisions at a centre-of-mass energy of$$\sqrt{s}=$$$\sqrt{s}=$13 $$\text {TeV}$$$\text{TeV}$, recorded by the ATLAS detector at the LHC from 2015 to 2018 and corresponding to an integrated luminosity of 139 fb$$^{-1}$$${}^{-1}$, are analysed. Vector-like partnersTandBof the top and bottom quarks are considered, as is a vector-likeXwith charge$$+5/3$$$+5/3$, assuming their decay into aW,Z, or Higgs boson and a third-generation quark. No significant deviations from the Standard Model expectation are observed. Upper limits on the production cross-section ofTandBquark pairs as a function of their mass are derived for various decay branching ratio scenarios. The strongest lower limits on the masses are 1.59 $$\text {TeV}$$$\text{TeV}$assuming mass-degenerate vector-like quarks and branching ratios corresponding to the weak-isospin doublet model, and 1.47 $$\text {TeV}$$$\text{TeV}$(1.46 $$\text {TeV}$$$\text{TeV}$) for exclusive$$T \rightarrow Zt$$$T\to Zt$($$B/X \rightarrow Wt$$$B/X\to Wt$) decays. In addition, lower limits on theTandBquark masses are derived for all possible branching ratios.