Previous educational articles on microfluidic technology mainly focused on continuous microfluidics, so we set up an undergraduate laboratory experiment to introduce droplet microfluidics to students. Students can understand the concept of microfluidic channels and the principles of droplet microfluidics, prepare polydimethylsiloxane (PDMS)…

The addition of a small excess of triethyl orthoformate to an alcoholic mixture of NiCl[subscript 2]·6H[subscript 2]O and triphenylphosphine (PPh[subscript 3]) results in an increase in the typical isolated yield of [NiCl[subscript 2](PPh[subscript 3])[subscript 2]] from below 50% to over 85%. The impact of water when present in the reaction…

Electrochemistry represents a powerful sustainable method for chemical synthesis; however, its widespread application is limited due to the lack of exposure and appropriate basic training of synthetic chemists and engineers in electrochemistry and electrochemical engineering. The introduction of diverse laboratory practices to the current…

We investigated a very long chain falling from the pile on the edge of a table to the floor both experimentally and theoretically. In this very simple and novel configuration we showed that the velocity of the chain quickly converges to its asymptotic value, and that the steady-state velocity is proportional to the square root of the height of the…

The purpose of the study is to explore how pre-service teachers perceive buoyancy force affecting an object in a liquid and identify their misunderstandings and misconceptions. Pre-service teachers were interviewed to reveal their understandings of an object' floating, suspending and sinking in a liquid. In addition, they were asked about how an…

This exploratory qualitative study examined science teacher enactment of crosscutting concepts (CCCs), a core aspect of Next Generation Science Standards (NGSS) three-dimensional learning, which also includes disciplinary core ideas and science and engineering practices (SEPs). We collected naturalistic observational and interview data from 13…

We study the variation of the apparent weight of an object with height above the surface of a planet with a (buoyant) atmosphere. Interestingly, this variation depends on two competing factors--the reduced gravitational acceleration (which acts to reduce the weight with increasing height) and the reduced buoyancy force in the progressively less…

The Young-Laplace (Y-L) equation relates the pressure difference across the interface of two fluids (such as air and water) to the curvature of the interface. The pressure rises on crossing a convex interface such as a rain drop and falls on crossing a concave interface such as the meniscus of water in a glass capillary. The relation between…

Our first experience of dimension typically comes in the intuitive Euclidean sense: a line is one dimensional, a plane is two dimensional, and a volume is three dimensional. However, following the work of Mandelbrot, systems with a fractional dimension, "fractals," now play an important role in science. The novelty of encountering…

In this paper, a simple method is described for visually demonstrating that the wavelength of light reduces when entering a medium of higher refractive index. When a violet laser (405 nm) is reflected off the surface of a Blu-ray disc (track spacing 320 nm) diffraction cannot occur since the wavelength is greater than the track spacing. However,…

Applying the idea of green chemistry, we extended an esterification teaching experiment with isoamyl alcohol and acetic acid and reused isoamyl acetate in the transesterification reaction with KOH as the catalyst. As a result, isoamyl alcohol was produced and could be reused for the teaching experiment. The simplified experimental method achieved…

"k[subscript cat]/K[subscript M]" is a fundamental kinetic parameter as important as "k[subscript cat]" in enzyme kinetics. Although the parameter provides critical information on how the enzyme lowers the energy barriers along the reaction pathway for catalysis, "k[subscript cat]/K[subscript M]" is frequently…

Argumentation skills are important for students to analyze and evaluate critical information, especially in complex science issues. Socio-Scientific Real-world Inquiry [SSRI] learning helps students develop deep scientific understanding and the ability to build evidence-based arguments in a real context. This study aimed to examine the…

This study examines the effects of the pedagogical use of context-rich problems on motivation and learning, as compared to traditional problems, in mechanical physics courses at the college level. The results indicate that the treatment has appreciable outcomes on conceptual learning gain, on the perception of task value and on a perceived sense…

Introductory biology is a gateway course for majors and other science, technology, engineering, and mathematics (STEM) disciplines. Despite the importance of chemistry content knowledge for understanding biology, the relationship between chemistry knowledge and prior coursework and biology course performance is understudied. We used an opportunity…