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WO3/WS2 core/shell nanowires were synthesized using a scalable fabrication method by combining wet chemical etching and chemical vapor deposition (CVD). Initially, WO3 nanowires were formed through wet chemical etching using a potassium hydroxide (KOH) solution, followed by oxidation at 650 °C. These WO3 nanowires were then sulfurized at 900 °C to form a WS2 shell, resulting in WO3/WS2 core/shell nanowires with diameters ranging from 90 to 370 nm. The synthesized nanowires were characterized using scanning electron microscopy (SEM), Raman, energy-dispersive X-ray spectroscopy (EDS), X-ray diffractometry (XRD), and transmission electron microscopy (TEM). The shell is composed of 2D WS2 layers with uniformly spaced 2D layers as well as the atomically sharp core/shell interface of WO3/WS2. Notably, the WO3/WS2 heterostructure nanowires exhibited a unique negative photoresponse under visible light (405 nm) illumination. This negative photoresponse highlights the importance of interface engineering in these heterostructures and demonstrates the potential of WO3/WS2 core/shell nanowires for applications in photodetectors and other optoelectronic devices. 

The Success and Retention of Students using Multiple-Attempt Testing in Fundamental Engineering Courses: Dynamics and Thermodynamics First name Last name1, First name Last name 1, First name Last name 2, First name Last name 2, First name Last name 3, and First name Last name 1 1Department One 2Department two 3Department Three University Abstract The notion behind Multiple-Attempt Testing continues to be investigated for its benefits in terms of students’ overall success and their retention in fundamental engineering courses. Two engineering courses were delivered in mixed-mode in Spring 2023 (post-COVID): Dynamics and Thermodynamics, whose results were compared to the same courses given in the same semester, four years earlier, delivered in mixed-mode in Spring 2019 (pre-COVID). All four courses were large classes ranging from 167 students for Spring 2023 in Dynamics to 267 students in Thermodynamics for the same Spring 2023 semester. For both courses, there were three tests during the semester. In Spring 2019, students were given a five-day window to conduct their tests in the testing center (TC). Facilitated by the Learning Management System (LMS), the grades were instantly uploaded into CANVAS. Once the test closed, students were allowed to see their work with a teaching-assistant to learn from mistakes and claim some partial credit where possible. However, in Spring 2023, for both courses, students were given three tests during the semester with three attempts each, as well as a make-up final cumulative examination, also with three attempts, for those who wanted to improve their grades. No partial credit was given in any attempt of any test or the final examination. Each attempt was open for two days and the students were allowed to see their tests after each attempt, learn from mistakes, and prepare better for the next attempt. The effectiveness of this testing-interwoven-learning method lies in the fact that students are comfortable and less anxious to do their tests knowing they have other chances, can learn from their mistakes and focus their attention on their weaknesses, enhance their knowledge, and do better in the next attempt. With this self-paced method students learn a lot on their own given the amount of videos provided them. The study shows a substantial decrease in the failure rate, 65% and the overall DWF decreased by more than 40% in both courses. This suggests students aspired to do well in every attempt, or even if they failed all three tests, they would still have a final examination that could save them, which reduced the overall DWF. A survey was also conducted, revealing more than 70% of students preferred this method of testing and learning in future courses. 

Flexible sensors with low fabrication cost, high sensitivity, and good stability are essential for the development of smart devices for wearable electronics, soft robotics, and electronic skins. Herein, we report a nanocomposite material based on carbon nanotube and metal oxide semiconductor for ultraviolet (UV) sensing applications, and its sensing behavior. The sensors were prepared by a screen-printing process under a low-temperature curing condition. The formation of a conducting string node and a sensing node could enhance a UV sensing response, which could be attributed to the uniform mixing of functionalized multi-walled carbon nanotubes and zinc oxide nanoparticles. A fabricated device has shown a fast response time of 1.2 s and a high recovery time of 0.8 s with good mechanical stability.