OPAC - Pencarian Artikel Jurnal & Majalah Library USD
Menampilkan semua artikel (Halaman 527 dari 34170, Total: 341698 data)
A matrix exponential approach to radioactive decay equations
klik untuk membaca file PDF
| Pengarang | : | - |
| Nama Majalah/Jurnal | : | American Journal of Physics |
| Volume / Edisi | : | 86 (No. 12) |
| Halaman | : | 909–913 |
| Abstrak | : | This paper demonstrates how the Bateman solution to the radioactive decay equations can be derived using the matrix exponential function. It is shown that when the matrix has triangular form, the elements for the matrix function satisfy a recursive form from which a simple routine can be developed to perform calculations. A compact expression for the solution is found by showing that these elements can also be represented in terms of divided differences of the exponential function. With little additional effort, the approach can be developed to yield solutions to more general forms of these equations. |
MERENCANAKAN SISTEM INFORMASI TERPADU
| Pengarang | : | - |
| Nama Majalah/Jurnal | : | Berita Arsip Nasional RI |
| Volume / Edisi | : | -/26, JUNI (No. 26) |
| Halaman | : | 16-22 |
| Abstrak | : | - |
The Fourier spectrum of a singing wine glass
| Pengarang | : | - |
| Nama Majalah/Jurnal | : | American Journal of Physics |
| Volume / Edisi | : | 87 (No. 10) |
| Halaman | : | 829-835 |
| Abstrak | : | The phenomenon of the singing wineglass is familiar to many. Most people have run a finger along the rim of a wine glass with the right speed and pressure to get it to whistle a tone or perhaps heard a glass harmonica being played. However, have you ever noticed and wondered why the vibrations caused by a finger on a glass produce a pulsating sound, rather than a steady, constant-amplitude vibration? Further exploration reveals that the sound and pulsations of a wine glass vary depending on the way the wine glass is stimulated. In this paper, we investigate and model the characteristic sounds produced by three different cases: the pulsating sound exhibited by a finger run along the rim of a wine glass, the steady tone produced by a stationary finger on a rotating wine glass, and the decaying pulsations exhibited by a struck rotating wine glass. Analyzing the qualitative differences among these three cases provides opportunities for students to hone experimental, modeling, and data analysis skills in an intermediate level undergraduate experimental physics course. |
Using history to foster critical scientific thinking: Aristotle and Galileo's debate resolved through high-speed motion tracking in the classroom
| Pengarang | : | Josef M. Stadlbauer |
| Nama Majalah/Jurnal | : | American Journal of Physics |
| Volume / Edisi | : | 86 (No. 12) |
| Halaman | : | 903–908 |
| Abstrak | : | In his Discorsi, Galileo aimed to correct centuries of Aristotelian “unreason” concerning the physics of falling objects by introducing a thought experiment that pointed out contradictions when combinations of one light and one heavy body are dropped. Inspired by Galileo's story, we sought to formulate research questions and design experiments for students to enable independent learning based on the history of science. The experiments involve commonly used or inexpensive equipment and free software, and show that Aristotle and Galileo did not disagree about falling objects, but were focusing on different kinds of motion. We assess data generated by high-speed video motion tracking of the fall of various combinations of simple handmade paper cones, following closely the discussion between Simplicio, Salviati and Sagredo in the Discorsi, and demonstrate that every statement in Galileo's reductio ad absurdum holds true and that his argument is in fact free of contradiction. |
Coalitional Resistance: Challenging Racialized and Gendered Oppression in Teacher Education
| Pengarang | : | Hsieh, Betina,Nguyen, Huong Tran |
| Nama Majalah/Jurnal | : | Journal of Teacher Education |
| Volume / Edisi | : | 72 (No. 3) |
| Halaman | : | 355-367 |
| Abstrak | : | In this article, the authors push back against "unnatural invisibility" and stereotypes of Asian American women by introducing a culturally informed coalitional resistance framework. Drawing from elements of Community Cultural Wealth (CCW) and AsianCrit, we use the framework to discuss the evolving microaggressions we have faced in teacher education spaces and how we have survived through them. We examine marginalizing experiences each of us has faced along multiple axes of oppression across our careers, the forms of resistance we could ( or chose not to) enact in specific contexts and moments, and how, through coalitional resistance, we are reclaiming our collective right to thrive and be recognized for our contributions as teacher educators. We conclude by offering implications of coalitional resistance for fellow teacher educators of color and those who wish to support them. |
Rebounding motion of a highly elastic ball between two parallel matte plates
| Pengarang | : | - |
| Nama Majalah/Jurnal | : | American Journal of Physics |
| Volume / Edisi | : | 86 (No. 12) |
| Halaman | : | 893-902 |
| Abstrak | : | If a highly elastic ball is thrown into the space between two parallel matte plates, under some circumstances, the ball might be projected back in the opposite direction after bounding a few times. In this paper, a theoretical model, which describes the transformation of the ball's centroid velocity and angular velocity before and after a collision, as well as its motion in the air between two collisions, is established and then verified by experiments. In addition, the coefficient of restitution between the ball and the plates are fitted. Numerical simulations were performed to discuss the conditions under which the ball would rebound back and its various rebounding modes that might exist. |
REKAM MEDIS DAN KESEHATAN (MEDICAL RECORD) DALAM KEDUDUKANNYA SEBAGAI INFORMASI PENUNJANG SISTEM KESEHATAN NASIONAL
| Pengarang | : | Gemala Rabi`ah Hatta |
| Nama Majalah/Jurnal | : | Berita Arsip Nasional RI |
| Volume / Edisi | : | -/26, JUNI (No. 26) |
| Halaman | : | 1-15 |
| Abstrak | : | - |
Faraday induction from point-charge fields
| Pengarang | : | - |
| Nama Majalah/Jurnal | : | American Journal of Physics |
| Volume / Edisi | : | 87 (No. 10) |
| Halaman | : | 824-828 |
| Abstrak | : | Interpreting Faraday's law of induction has been a challenge for students, because this law involves abstract and sophisticated concepts such as the magnetic flux, given by a surface integral, and the electromotive force, given by a line integral. Besides that, Faraday's law is not clear with respect to the sources of the different fields of force, electric and magnetic, involved simultaneously in the phenomenon of induction. We discuss Faraday's electromagnetic induction through the magnetic and electric fields of point-charges in a quasistatic regime. From this perspective, we show that the results of Faraday's experiments that led to the discovery of electromagnetic induction can be understood in terms of the electric acceleration and velocity fields of point charges. |
Mathematics Teachers' Knowledge, Networks, Practice, and Change in Instructional Visions
| Pengarang | : | - |
| Nama Majalah/Jurnal | : | Journal of Teacher Education |
| Volume / Edisi | : | 72 (No. 3) |
| Halaman | : | 342-354 |
| Abstrak | : | An instructional vision is the discourse that teachers or others currently employ to characterize the kind of "ideal classroom practice" to which they aspire but have not yet necessarily mastered. In mathematics education, prior work has demonstrated relations between teachers' instructional vision and a variety of aspects of their classroom practice and professional pursuits. We examined what might contribute to teachers' development of mathematics instructional visions through a quantitative analysis of a longitudinal data set collected in four urban school districts. Controlling for instructional vision in the prior year, we found middle school mathematics teachers' current instructional vision to be related to their prior mathematical knowledge for teaching, their prior instructional practice, and their colleagues' prior instructional visions-with the strength of the relation depending on the density of teachers' advice networks. Based on these findings, we discuss implications for both inservice teacher professional development and preservice teacher education. |
Race-Visible Teacher Education: A Review of the Literature From 2002 to 2018
| Pengarang | : | - |
| Nama Majalah/Jurnal | : | Journal of Teacher Education |
| Volume / Edisi | : | 72 (No. 3) |
| Halaman | : | 329-341 |
| Abstrak | : | In this review of the literature, we draw on critical race theory, critical whiteness studies, and critical pedagogy to exami,1e teacher educators' race-visible efforts in preservice teacher education and inservice teacher professional development. Our review specifically centers on race and racism in teacher education because race is often silenced or largely unaddressed in teacher education programs and teacher professional learning. Through a systematic search of electronic databas,.'s and ;; hand search of journals in this research area, we located 39 peer-reviewed articles published at the intersection of mu:. wt:ite teachers, and teacher education. Findings reveal the kinds of race-visible instructional practices used by teacher edurntors to scaffold race consciousness as well as larger themes teacher educators and education researchets encounter in their work related to race with preservice and inservice educators. We conclude with a discussion of our findings ::ind offer fuwre directions for continued research and practice. |