Quantum and Quasiclassical Dynamics of the ${\rm\bf C}(\bf ^3P)$ + ${\rm\bf H_2}(\bf ^1\Sigma_g^+)$ $\rightarrow$ ${\rm\bf H}(\bf ^2S)$ + ${\rm\bf CH}(\bf ^2\Pi)$ reaction: Coriolis Coupling Effects and Stereodynamics

The dynamics of ${\rm\bf C}$ + ${\rm\bf H_2}$ $\rightarrow$ ${\rm\bf H}$ + ${\rm\bf CH}$ reaction is theoretically studied using the quasiclassical trajectory and quantum mechanical wave packet methods. The analysis of reaction probabilities, integral cross sections and rate coefficients reveal the essential coriolis coupling effects in the quantum mechanical wave packet calculations. The calculated polarization-dependent differential cross section, P($\theta_r$) and P($\phi_r$) show that the $\bf j'$ of product rotational angular momentum is not only aligned along the y-axis and the direction of the vector $\bf x+z$, but also strongly oriented along the positive y-axis.

Ultrafast four-dimensional imaging of cardiac mechanical wave propagation with sparse optoacoustic sensing

Propagation of electromechanical waves in excitable heart muscles follows complex spatiotemporal patterns holding the key to understanding life-threatening arrhythmias and other cardiac conditions. Accurate volumetric mapping of cardiac wave propagation is currently hampered by fast heart motion, particularly in small model organisms. Here we demonstrate that ultrafast four-dimensional imaging of cardiac mechanical wave propagation in entire beating murine heart can be accomplished by sparse optoacoustic sensing with high contrast, ∼115-µm spatial and submillisecond temporal resolution. We extract accurate dispersion and phase velocity maps of the cardiac waves and reveal vortex-like patterns associated with mechanical phase singularities that occur during arrhythmic events induced via burst ventricular electric stimulation. The newly introduced cardiac mapping approach is a bold step toward deciphering the complex mechanisms underlying cardiac arrhythmias and enabling precise therapeutic interventions.

Pembelajaran Gelombang Bunyi Menggunakan Alat Musik Suling dan Gawai pada Pelajaran IPA SMP di Masa Pandemi Covid-19

ABSTRACTThe COVID-19 pandemic requires teachers to think carefully and creatively in designing learning so that it remains interactive and appropriate to achieve the learning goals. Physics learning with using a flute and a smartphone described in this paper is the result of a thought process about how students can still conduct experiments from home using simple equipment to measure the speed of sound in the air and at the same time learn the concepts of loudness and pitch of sound. A total of 37 eighth grade students in 2020/2021 academic year and 23 students in 2018/2019 acadeymic year at a private junior high school in Bekasi were involved in a pre-experimental study with a one-group posttest only design. A set of 10-item multiple-choice diagnostic tests taken from the Mechanical Wave Conceptual Survey and summative tests in the form of structured questions were arranged to test students' conceptual understanding after receiving sound wave learning. The average of diagnostic test and summative test in the 2018/2019 and 2020/2021 academic years were 30, 48 and 60 respectively out of 100 with a summative test completion percentage of 35% in 2018/2019 and 70% in 2020/2021 . Keywords: physics experiment, sound waves, recorder, smartphoneABSTRAK Masa pandemi Covid-19 menuntut guru untuk terus berpikir secara hati-hati dan kreatif dalam merancang pembelajaran agar tetap interaktif dan tepat mencapai tujuan pembelajaran yang ditetapkan. Pembelajaran dengan menggunakan suling dan berbantuan gawai yang dipaparkan dalam tulisan ini merupakan hasil dari proses berpikir tentang bagaimana siswa tetap dapat melakukan eksperimen dari rumah memanfaatkan peralatan sederhana untuk mengukur kelajuan gelombang bunyi di udara dan sekaligus mempelajari konsep kekerasan bunyi (loudness) dan tinggi nada (pitch) bunyi. Siswa kelas delapan sebanyak 37 siswa tahun ajaran 2020/2021 dan 23 siswa tahun ajaran 2018/2019 pada salah satu sekolah menengah pertama swasta di Kota Bekasi dilibatkan dalam penelitian pre-experiment dengan desain one-group posttest only. Seperangkat tes diagnostik berbentuk pilihan ganda sebanyak 10 butir yang diambil dari Mechanical Wave Conceptual Survey dan tes sumatif berbentuk uraian disusun untuk menguji pemahaman konsep siswa setelah mendapatkan pembelajaran gelombang bunyi. Rata-rata tes diagnostik dan tes sumatif pada tahun ajaran 2018/2019 dan 2020/2021 berturut-turut sebesar 30, 48 dan 60 dari maksimum nilai 100 dengan persentase ketuntasan tes sumatif sebesar 35% di 2018/2019 dan 70% di 2020/2021.Kata kunci: eksperimen fisika, gelombang bunyi, suling, gawai

Development of Physics Learning Media based on Guided Inquiry Model to Improve Students' Concepts Mastery and Creativity

This study aims to develop learning media based on guided inquiry models to improve students' concepts mastery and creativity in physics learning in senior high schools. The learning media in question is a ripple tank to explain the characteristics of a mechanical wave. Development research with the 4D model (define, design, development, dissemination) was conducted in this study, where the learning media developed met the criteria of validity, practicality, and effectiveness in improving students' concepts mastery and creativity. Evaluation of the learning media validity is carried out through a validation mechanism where the media is validated by 3 validators (media experts), while evaluation of the practicality and effectiveness of learning media through its implementation in class involves students in two schools in Mataram City - Indonesia. The results of the study show that the learning media with the guided inquiry model are valid, practical, and effective in improving students' concepts mastery and creativity in learning physics. The results of further studies are described in this article

SOLITARY TRANSMISSION OF NEURONAL SIGNALS APPROACHED VIA HE'S SEMI INVERSE METHOD

An investigation of neuronal signal transmission is intended in this paper through the establishment of solitary wave solutions for the improved Heimburg Jackson model governing the propagation of the mechanical wave in biomembranes. The computation of soliton solutions is carried out employing He's semi inverse variational principle. The role of nonlinearity and dispersive effects in the solitonic propation is correlated to the role of compressibility, elasticity, and inertia over the neuronal signal transmission in the unilamellar DPPC vesicles at T = 45o. The study reveals that He's semi inverse method is a direct and effective algebraic method to study the experimental features of the nerve pulse in the biomembranes.

On Whether People Have the Capacity to Make Observations of Mutually Exclusive Physical Phenomena

It has been shown by Einstein, Podolsky, and Rosen that in quantum mechanics one of two different wave functions predicting specific values for quantities represented by non-commuting Hermitian operators can characterize the same physical system, without a physical interaction responsible for which wave function is realized in a measurement. This result means that one can make predictions regarding mutually exclusive features of a physical system. It is important to ask whether people can make observations of mutually exclusive phenomena. Our everyday experience informs us that a human observer is capable of observing one set of physical circumstances at a time. Evidence from psychology, though, indicates that people may have the capacity to make observations of mutually exclusive physical phenomena, even though this capacity in not generally recognized. Working independently, Sigmund Freud and William James provided some of this evidence. How the nature of the quantum mechanical wave function is associated with the problem posed by Einstein, Podolsky, and Rosen is addressed at the end of the paper.