The European Physical Journal Plus最新文献_第3页

Semi-analytical solution of Graetz–Brinkman problem combined with non-Newtonian Ellis fluid flow in a passive channel 非牛顿Ellis流体在被动通道中流动的Graetz-Brinkman问题的半解析解

IF 3.4 3区物理与天体物理

The European Physical Journal Plus Pub Date : 2023-11-04 DOI: 10.1140/epjp/s13360-023-04632-8

Zeeshan Asghar, Muhammad Waris Saeed Khan, Wasfi Shatanawi, Muhammad Asif Gondal

{"title":"Semi-analytical solution of Graetz–Brinkman problem combined with non-Newtonian Ellis fluid flow in a passive channel","authors":"Zeeshan Asghar, Muhammad Waris Saeed Khan, Wasfi Shatanawi, Muhammad Asif Gondal","doi":"10.1140/epjp/s13360-023-04632-8","DOIUrl":"10.1140/epjp/s13360-023-04632-8","url":null,"abstract":"<div><p>Heat transfer analysis of non-Newtonian fluids has numerous applications in the industrial and chemical engineering fields. Inspired by the prevalence of non-Newtonian liquids in chemical industries, this article aims to elaborate on the Graetz–Brinkman problem for an Ellis fluid inside the horizontal channel. The developed heat equation is first solved employing an analytical approach, i.e., the separation of variables, and then, the numerical solution of the eigenvalue problem is obtained by employing the MATLAB function bvp4c. The simulation is carried out for the situation of the isothermal walls. The temperature distribution under the impact of Brinkman number and model parameters is analyzed through various graphs. A comparison between the Ellis fluid and Newtonian fluid is also expounded. The results reveal that while using Ellis fluid, a higher heat transfer rate is achieved as compared to Newtonian fluid. The results may improve our comprehension of how non-Newtonian fluids transmit heat in a variety of situations. Furthermore, it is thought that this approach has made a significant contribution to the chemical sector in terms of developing and enhancing various types of thermal equipment.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"138 11","pages":""},"PeriodicalIF":3.4,"publicationDate":"2023-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71908916","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Beam merging assisted by a bent crystal 弯曲晶体辅助光束合并

IF 3.4 3区物理与天体物理

The European Physical Journal Plus Pub Date : 2023-11-04 DOI: 10.1140/epjp/s13360-023-04610-0

W. Scandale, F. Cerutti, L. S. Esposito, S. Gilardoni, R. Losito, G. I. Smirnov, A. Giribono, M. Bauce, F. Collamati, P. Valente, A. Variola, F. Galluccio, G. Hall, M. Pesaresi, K. Uchida, R. Rossi

引用次数: 0

Tunable electronic structures in C3N/WSe2 van der Waals heterostructure by biaxial strain and external electric field 双轴应变和外电场作用下C3N/WSe2范德华异质结构中的可调谐电子结构

IF 3.4 3区物理与天体物理

The European Physical Journal Plus Pub Date : 2023-11-04 DOI: 10.1140/epjp/s13360-023-04556-3

Qin Zhang, Pei Chen, Qin Liu, He Huang, Xiaoyang Ma, Tingting Song, Jiehong Lei

{"title":"Tunable electronic structures in C3N/WSe2 van der Waals heterostructure by biaxial strain and external electric field","authors":"Qin Zhang, Pei Chen, Qin Liu, He Huang, Xiaoyang Ma, Tingting Song, Jiehong Lei","doi":"10.1140/epjp/s13360-023-04556-3","DOIUrl":"10.1140/epjp/s13360-023-04556-3","url":null,"abstract":"<div><p>Van der Waals heterostructures have a wide range of applications in the semiconductor industry. Based on the superior properties of C<sub>3</sub>N and WSe<sub>2</sub> monolayers, the stability and electronic properties of C<sub>3</sub>N/WSe<sub>2</sub> vdW heterostructure under strain and external electric field are studied using density functional theory. The results show that the C<sub>3</sub>N/WSe<sub>2</sub> vdW heterostructure has a type-I band alignment and possesses a direct band gap of 0.397 eV. Furthermore, the electric field and biaxial strain not only modulate the C<sub>3</sub>N/WSe<sub>2</sub> band gap, but also induce band alignment (type I to type II) and a direct gap to an indirect gap transition, even undergoing semiconductor-to-metal transition. These results suggest that tunable electronic properties of C<sub>3</sub>N/WSe<sub>2</sub> heterostructure has the potential to be applied in semiconductor devices, especially optoelectronic devices.</p><h3>Graphical abstract</h3>\u0000 <div><figure><div><div><picture><source><img></source></picture></div></div></figure></div>\u0000 </div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"138 11","pages":""},"PeriodicalIF":3.4,"publicationDate":"2023-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71908915","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Equilibrium properties of 2D electron systems in quantum wells and graphene 量子阱和石墨烯中二维电子系统的平衡性质

IF 3.4 3区物理与天体物理

The European Physical Journal Plus Pub Date : 2023-11-04 DOI: 10.1140/epjp/s13360-023-04586-x

M. A. Hidalgo

引用次数: 0

On a finite-time optimization of coupled electric engines by using a freedom degrees reduction procedure 用自由度折减法对耦合电动发动机进行有限时间优化

IF 3.4 3区物理与天体物理

The European Physical Journal Plus Pub Date : 2023-11-04 DOI: 10.1140/epjp/s13360-023-04627-5

A. Ocampo-García, M. A. Barranco-Jiménez, F. Angulo-Brown

引用次数: 0

Numerical simulations with mitigation strategies on Barabási–Albert network for the spread of coronavirus in Pakistan Barabási–Albert网络上冠状病毒在巴基斯坦传播的数值模拟和缓解策略

IF 3.4 3区物理与天体物理

The European Physical Journal Plus Pub Date : 2023-11-03 DOI: 10.1140/epjp/s13360-023-04628-4

Abdul Rauf Nizami, Muhammad Rafiq, Mustafa Inc, Hammad Alotaibi, Nadeem Ahmad

引用次数: 0

Construction of chirped propagation with Jacobi elliptic functions for the nonlinear Schrödinger equations with quadratic nonlinearity with inter-modal and spatio-temporal dispersions 具有模态间和时空色散的二次非线性Schrödinger方程的Jacobi椭圆函数啁啾传播的构造

IF 3.4 3区物理与天体物理

The European Physical Journal Plus Pub Date : 2023-11-03 DOI: 10.1140/epjp/s13360-023-04626-6

A. H. Tedjani, Aly R. Seadawy, Syed T. R. Rizvi, Emad Solouma

引用次数: 0

Observational constraints on the quantum Einstein-Aether model 量子Einstein-Aether模型的观测约束

IF 3.4 3区物理与天体物理

The European Physical Journal Plus Pub Date : 2023-11-03 DOI: 10.1140/epjp/s13360-023-04615-9

F. G. Alvarenga, L. A. M. Diniz, S. V. B. Gonçalves, G. A. Monerat, E. V. Corrêa Silva

{"title":"Observational constraints on the quantum Einstein-Aether model","authors":"F. G. Alvarenga, L. A. M. Diniz, S. V. B. Gonçalves, G. A. Monerat, E. V. Corrêa Silva","doi":"10.1140/epjp/s13360-023-04615-9","DOIUrl":"10.1140/epjp/s13360-023-04615-9","url":null,"abstract":"<div><p>We build a classical cosmological model by applying the ADM formalism to a modified theory of gravitation, based on General Relativity. The Einstein-Aether theory couples a timelike vector field to the metric, selecting a preferred local frame of reference and thus breaking the Lorentz symmetry. The intensity of this coupling is determined by dimensionless constants, and in this work, the values of these constants were chosen in accordance with the existing theoretical and observational constraints. The use of the ADM formalism generates the loss of a time-type variable known as the “time problem” which, in this work, is approached phenomenologically by the introduction of the material content of the Universe as a perfect baryonic fluid. This is the so-called Schutz formalism, in which this fluid is described by six potential fields, and a new time-like variable is defined from the fluid entropy. We consider a general model, for any perfect baryonic fluid, in a homogeneous and isotropic FLRW Universe. This cosmological model has two degrees of freedom: the scale factor <i>a</i> and the time <span>(tau )</span>. The Wheeler-DeWitt quantization scheme is then applied, and the wave function of the Universe is obtained. In this work we consider the solutions of the Wheeler-DeWitt equation that satisfy the boundary condition in which the derivative of the wave function at <span>(a=0)</span> is zero. We apply to this quantum cosmological model the many-worlds interpretation and the de Broglie-Bohm interpretation of quantum mechanics, verifying the possibility of avoiding a singularity at the beginning of the Universe.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"138 11","pages":""},"PeriodicalIF":3.4,"publicationDate":"2023-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71908715","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A regular metric does not ensure the regularity of spacetime 正则度量不能保证时空的正则性

IF 3.4 3区物理与天体物理

The European Physical Journal Plus Pub Date : 2023-11-03 DOI: 10.1140/epjp/s13360-023-04624-8

Manuel E. Rodrigues, Henrique A. Vieira

{"title":"A regular metric does not ensure the regularity of spacetime","authors":"Manuel E. Rodrigues, Henrique A. Vieira","doi":"10.1140/epjp/s13360-023-04624-8","DOIUrl":"10.1140/epjp/s13360-023-04624-8","url":null,"abstract":"<div><p>In this paper we try to clarify that a regular metric can generate a singular spacetime. Our work focuses on a static and spherically symmetric spacetime in which regularity exists when all components of the Riemann tensor are finite. There is work in the literature that assumes that the regularity of the metric is a sufficient condition to guarantee it. We study three regular metrics and show that they have singular spacetime. We also show that these metrics can be interpreted as solutions for black holes whose matter source is described by nonlinear electrodynamics. We analyze the geodesic equations and the Kretschmann scalar to verify the existence of the curvature singularity. Moreover, we use a change of the line element <span>(r rightarrow sqrt{r^2+a^2})</span>, which is a process of regularization of spacetime already known in the literature. We then recompute the geodesic equations and the Kretschmann scalar and show that all metrics now have regular spacetime. This process transforms them into black-bounce solutions, two of which are new. We have discussed the properties of the event horizon and the energy conditions for all models.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"138 11","pages":""},"PeriodicalIF":3.4,"publicationDate":"2023-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71908716","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Thermal effects on the baryon–quark phase transition in hot hybrid neutron stars: a statistical mean-field baryonic model with the standard NJL model for deconfined quarks 热混合中子星重子-夸克相变的热效应：一个具有标准NJL模型的统计平均场重子模型

IF 3.4 3区物理与天体物理

The European Physical Journal Plus Pub Date : 2023-11-02 DOI: 10.1140/epjp/s13360-023-04611-z

S. A. Ghaemmaghami, M. Ghazanfari Mojarrad

{"title":"Thermal effects on the baryon–quark phase transition in hot hybrid neutron stars: a statistical mean-field baryonic model with the standard NJL model for deconfined quarks","authors":"S. A. Ghaemmaghami, M. Ghazanfari Mojarrad","doi":"10.1140/epjp/s13360-023-04611-z","DOIUrl":"10.1140/epjp/s13360-023-04611-z","url":null,"abstract":"<div><p>We investigate the thermal effects on the baryon–quark phase transition (PT), utilizing the Maxwell construction (MC) in an isentropic analysis. In order to model the structure and composition of hot hybrid neutron stars (HHNSs) with <span>(beta)</span>-equilibrated dense matter in the presence (absence) of trapped neutrinos, we use a statistical model which agrees with the Thomas–Fermi (TF) approximation for the baryonic phase and the Nambu–Jona-Lasinio (NJL) model for the deconfined quark phase. Our results show that neutrino trapping can provide a considerable softening of the equation of state EOS in the baryon–quark coexistence phase, compared with the situation governed by untrapped (free-streaming) neutrinos. Having a weak dependence on the quark vector coupling constant in the pure quark phase, the temperature meets its maximum value at the threshold baryonic density for the occurrence of the baryon–quark PT. Based on the assumption of the conserved baryonic mass, all of our HHEOS lead to the stable mass structures for a HHNS.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"138 11","pages":""},"PeriodicalIF":3.4,"publicationDate":"2023-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71908971","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0