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Pandemic modeling with the game of life 用生命游戏制作大流行病模型
IF 0.9 4区 教育学
American Journal of Physics Pub Date : 2023-12-01 DOI: 10.1119/5.0166146
David Faux, Thesha Thavaraja, Alana Croucher
{"title":"Pandemic modeling with the game of life","authors":"David Faux, Thesha Thavaraja, Alana Croucher","doi":"10.1119/5.0166146","DOIUrl":"https://doi.org/10.1119/5.0166146","url":null,"abstract":"The generalized semi-classical game of life (gSCGOL) is a cellular automaton in which qubits evolve through repeated applications of birth, death, and survival operators. gSCGOL is used to model human–virus interactions during the COVID-19 pandemic by using cell “liveness” to be equivalent to the human population that is vulnerable to the disease. A match to the United Kingdom (UK) daily 7-day average COVID-19 deaths was achieved by daily changes to a parameter V representing the vulnerability of the population to the virus. The model predicts that the first COVID-19 virus entered the UK on December 22, 2019 with an uncertainty of ±1 days. The changes in the vulnerability V elucidate the human response to the unfolding pandemic during 2020, quantifying the impact of the lockdown, the relaxation of restrictions, and the opening and closing of schools. The model predicts that starting the first UK national lockdown one week earlier would have led to 40% fewer COVID-19-related deaths, equivalent to 17 000 lives.","PeriodicalId":7589,"journal":{"name":"American Journal of Physics","volume":" 18","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138611490","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"教育学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Molecular spectroscopy as a laboratory experiment: Measurement of important parameters of sodium diatomic molecules 作为实验室实验的分子光谱学：测量钠二原子分子的重要参数
IF 0.9 4区 教育学
American Journal of Physics Pub Date : 2023-12-01 DOI: 10.1119/5.0123126
Md Shakil Bin Kashem, Morgan Davies, Lok Pant, S. B. Bayram
{"title":"Molecular spectroscopy as a laboratory experiment: Measurement of important parameters of sodium diatomic molecules","authors":"Md Shakil Bin Kashem, Morgan Davies, Lok Pant, S. B. Bayram","doi":"10.1119/5.0123126","DOIUrl":"https://doi.org/10.1119/5.0123126","url":null,"abstract":"We present an inexpensive sodium molecular spectroscopy experiment for use in an advanced undergraduate laboratory course in physics or chemistry. The molecules were excited predominantly from the ground X1Σg+(v″ = 15) state to the B1Πu(v′ = 6) state using a commercially available 532-nm broadband diode laser. The laser-induced molecular fluorescence was measured using a miniature fiber-coupled spectrometer at a resolution of 0.5 nm. The spectral peak assignments were done by comparing the observed spectrum with the calculated Franck–Condon values. Important molecular constants such as fundamental frequency, anharmonicity, bond strength, and dissociation energy of the ground electronic state were determined by using the Birge–Sponer extrapolation method. The presence of highly visible blue glowing molecules along the green laser beam creates an engaging laboratory experience. Emphasis is placed on students developing their understanding of the molecular structure, practicing molecular spectroscopic techniques, and applying knowledge of light–matter interactions to a physical system.","PeriodicalId":7589,"journal":{"name":"American Journal of Physics","volume":" 2","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138618047","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"教育学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Paediatric Parotid Abscess: A Rare Presentation. 小儿腮腺脓肿:罕见的表现。
IF 0.8 4区 教育学
American Journal of Physics Pub Date : 2023-12-01 Epub Date: 2023-07-06 DOI: 10.1007/s12070-023-04030-7
Sounak Patra, Sauradeep Das, Prachurya Tamuli, Suvamoy Chakraborty
{"title":"Paediatric Parotid Abscess: A Rare Presentation.","authors":"Sounak Patra, Sauradeep Das, Prachurya Tamuli, Suvamoy Chakraborty","doi":"10.1007/s12070-023-04030-7","DOIUrl":"10.1007/s12070-023-04030-7","url":null,"abstract":"<p><p>Acute parotitis in children is a common occurrence with predisposing factors including ductal dysfunction, poor oral hygiene or dental infections, immunosuppression, dehydration, or a pre-existing Warthin's tumour. Bacterial or viral infections of the intra-parotid and peri-parotid lymph nodes or the parotid gland parenchyma results in inflammatory followed by suppurative changes which leads to formation of parotid abscess. Surgical drainage is necessary in parotid abscesses not responding to conservative management. Surgical intervention is invasive and has associated risks of injury to the facial nerve and poor cosmetic outcome. We present a case of parotid abscess in a 9-year-old female child which required surgical drainage. In literature, parotid gland abscess arising from a preceeding dental infection in paediatric age group is an uncommon occurence and limited number of cases have been documented. The first line of imaging is ultrasonographic examination of the parotid gland which adds on to the clinical examination. In combination with color doppler, sonography is of immense assistance for diagnosis and evaluation of therapeutic efficacy and also helps guide aspiration or incision and drainage.</p>","PeriodicalId":7589,"journal":{"name":"American Journal of Physics","volume":"57 1","pages":"4054-4056"},"PeriodicalIF":0.8,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10645870/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85477825","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"教育学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Metastable states in a 1D quantum system 一维量子系统中的嬗变态
IF 0.9 4区 教育学
American Journal of Physics Pub Date : 2023-12-01 DOI: 10.1119/5.0124407
J. Goff, Don C. Colladay
{"title":"Metastable states in a 1D quantum system","authors":"J. Goff, Don C. Colladay","doi":"10.1119/5.0124407","DOIUrl":"https://doi.org/10.1119/5.0124407","url":null,"abstract":"One-dimensional (1D) systems in which metastable states exist are physically important, but they are usually not discussed quantitatively in textbooks. This paper presents a relatively simple 1D system involving a piecewise-constant potential for which metastable states can be easily calculated using a computer algebraic system. The metastable-state wave functions are computed and plotted for various particle energies. The Breit–Wigner approximation is used to fit the resulting resonant structure in the transmission coefficient. Connections are made between the initial analysis and poles of the scattering matrix that corresponds to the potential.","PeriodicalId":7589,"journal":{"name":"American Journal of Physics","volume":"121 31","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138608374","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"教育学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Pendulum waves: A model of Thomae's function 钟摆波托马函数模型
IF 0.9 4区 教育学
American Journal of Physics Pub Date : 2023-12-01 DOI: 10.1119/5.0131936
Xiangdong Feng, Changhong Lu, Jurgen Schulte, Zengxu Shan, Gentong Liu
{"title":"Pendulum waves: A model of Thomae's function","authors":"Xiangdong Feng, Changhong Lu, Jurgen Schulte, Zengxu Shan, Gentong Liu","doi":"10.1119/5.0131936","DOIUrl":"https://doi.org/10.1119/5.0131936","url":null,"abstract":"The pendulum wave apparatus exhibits cyclic pendulum patterns, including wave-like motion and pendulums alignments. This work presents a complete analytical solution to the times and numbers of pendulum alignment, which is shown to be a subset of Thomae's function. Based on the properties of this function and basic number theory, a comprehensive analysis of pendulum patterns is presented.","PeriodicalId":7589,"journal":{"name":"American Journal of Physics","volume":" 14","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138620240","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"教育学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Using lock-in detection to build a barcode scanner 使用锁定检测构建条形码扫描器
IF 0.9 4区 教育学
American Journal of Physics Pub Date : 2023-12-01 DOI: 10.1119/5.0151621
Riley E. Alexander, Maya M. DiFrischia, Margaret J. Doubman, Stefany Fabian Dubon, Lily Goltz, Yuqian Li, Rebecca A. Long, Genevieve Love, Nina Martinez Diers, Matangi Melpakkam, Catie Robinson, Elizabeth M. Tompkins, Avalon L. B. Vanis, Xinrui Wang, Mallory Yu, Sarah E. Spielman, Michael W. Noel
{"title":"Using lock-in detection to build a barcode scanner","authors":"Riley E. Alexander, Maya M. DiFrischia, Margaret J. Doubman, Stefany Fabian Dubon, Lily Goltz, Yuqian Li, Rebecca A. Long, Genevieve Love, Nina Martinez Diers, Matangi Melpakkam, Catie Robinson, Elizabeth M. Tompkins, Avalon L. B. Vanis, Xinrui Wang, Mallory Yu, Sarah E. Spielman, Michael W. Noel","doi":"10.1119/5.0151621","DOIUrl":"https://doi.org/10.1119/5.0151621","url":null,"abstract":"Lock-in detection is a widely used experimental technique in which a weak signal is measured by modulating it at a particular frequency. Then, by detecting an experimental output at that frequency, the desired signal can be isolated from much larger-amplitude noise. Here, we report on the implementation and optimization of a homemade laser barcode scanner based on the lock-in technique. Our setup is comprised of components that are readily available in an undergraduate instructional laboratory. The successful transcription of the barcode into a digital signal was achieved, and this digital signal was collected with a simple computer and processed to reveal the encoded number.","PeriodicalId":7589,"journal":{"name":"American Journal of Physics","volume":"109 6","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138622985","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"教育学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Nonlinear oscillator acceleration and period variation with amplitude 非线性振荡器加速度和周期随振幅的变化
IF 0.9 4区 教育学
American Journal of Physics Pub Date : 2023-12-01 DOI: 10.1119/5.0139124
Peter F. Hinrichsen
{"title":"Nonlinear oscillator acceleration and period variation with amplitude","authors":"Peter F. Hinrichsen","doi":"10.1119/5.0139124","DOIUrl":"https://doi.org/10.1119/5.0139124","url":null,"abstract":"A classic nonlinear spring mass oscillator, the nonlinearity of which could be varied by changing the initial stretching of the spring, was used to investigate how the amplitude dependence of the period and the harmonic content depended on the nonlinearity. The oscillations were measured with a photogate and a MEMS accelerometer, allowing both the oscillation period and the Fourier components of the motion to be precisely determined. The results were in good agreement with theory.","PeriodicalId":7589,"journal":{"name":"American Journal of Physics","volume":" 4","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138621113","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"教育学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Comment on “Avoid propagation of typos with numerical methods” [Am. J. Phys. 89(1), 9 (2021)] 关于 "用数值方法避免错别字传播 "的评论 [Am. J. Phys. 89(1), 9 (2021)]
IF 0.9 4区 教育学
American Journal of Physics Pub Date : 2023-12-01 DOI: 10.1119/5.0167881
B. C. Reed
{"title":"Comment on “Avoid propagation of typos with numerical methods” [Am. J. Phys. 89(1), 9 (2021)]","authors":"B. C. Reed","doi":"10.1119/5.0167881","DOIUrl":"https://doi.org/10.1119/5.0167881","url":null,"abstract":"","PeriodicalId":7589,"journal":{"name":"American Journal of Physics","volume":"4 7","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138625488","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"教育学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
S-matrices for simple quantum systems 简单量子系统的s矩阵
4区 教育学
American Journal of Physics Pub Date : 2023-11-01 DOI: 10.1119/5.0078607
Leo de Wit
{"title":"<i>S</i>-matrices for simple quantum systems","authors":"Leo de Wit","doi":"10.1119/5.0078607","DOIUrl":"https://doi.org/10.1119/5.0078607","url":null,"abstract":"Scattering processes are a standard topic covered in introductory courses on quantum mechanics and particle physics. Unfortunately, a full mathematical treatment tends to be overwhelming for undergraduate students. This article introduces some toy models that are easy to comprehend but still contain the essential features of quantum theory. We define a Hilbert space with state vectors and use creation/annihilation operators to construct transition matrices and S-matrices. We show how perturbation theory gives rise to Feynman diagrams and Feynman rules. We also discuss how we can use symmetry and group theory to restrict what interactions are possible.","PeriodicalId":7589,"journal":{"name":"American Journal of Physics","volume":"403 6","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135112052","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"教育学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Oblique angle collisions between three or more billiard balls 三个或更多台球之间的斜角碰撞
4区 教育学
American Journal of Physics Pub Date : 2023-11-01 DOI: 10.1119/5.0119656
Rod Cross
{"title":"Oblique angle collisions between three or more billiard balls","authors":"Rod Cross","doi":"10.1119/5.0119656","DOIUrl":"https://doi.org/10.1119/5.0119656","url":null,"abstract":"Oblique angle collisions between two balls or two disks have been addressed by many authors. This paper describes oblique angle collisions between three or four billiard balls. Measurements and calculations are presented for cases where one ball is incident obliquely on two or three identical balls, which are in contact and initially at rest. Conservation laws alone are not sufficient to predict the outcome. Adding information about the impact forces on each ball (and ignoring friction forces) provides good theoretical agreement with experimental results.","PeriodicalId":7589,"journal":{"name":"American Journal of Physics","volume":"404 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135112047","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"教育学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
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