Physics Open最新文献

{"title":"Optimizing SOI-MESFET transistor performance at high frequencies by air-oxide layers in the channel and a nickel layer in the box","authors":"Hamed Mohammadi ,&nbsp;Younes Mohammadi","doi":"10.1016/j.physo.2024.100214","DOIUrl":"https://doi.org/10.1016/j.physo.2024.100214","url":null,"abstract":"<div><p>In this paper, we introduce a new transistor structure that has improved alternating current and direct current parameters compared to the basic structure. The cutoff frequency of the proposed structure is 33 GHz, while the cutoff frequency of the basic structure is 25.5 GHz. One important improvement is that the gate-drain parasitic capacitors in the channel area are nearly zero, thanks to the presence of an air layer between the gate and source electrodes and a nickle layer in the burried oxide. In addition to the alternating current parameters, the direct current parameters have also been strengthened. The maximum output power density for the new structure is 1.08 W/mm, compared to 0.455 W/mm for the normal structure. Furthermore, the breakdown voltage in the new structure has increased to 30 V, while the basic structure has a breakdown voltage of 16 V. These improvements are attributed to the transfer of the gate to the source and the increased distance from the drain region, as well as the presence of two layers of oxide and air on both sides of the gate. Consequently, the new structure can effectively operate at high voltages and powers.</p></div>","PeriodicalId":36067,"journal":{"name":"Physics Open","volume":"19 ","pages":"Article 100214"},"PeriodicalIF":0.0,"publicationDate":"2024-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666032624000127/pdfft?md5=3b2737c073eacd1a2c56373998608581&pid=1-s2.0-S2666032624000127-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140548541","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development of size and shape dependent model for various thermodynamic properties of nanomaterials","authors":"Soni Sharma ,&nbsp;Jagat Pal Singh","doi":"10.1016/j.physo.2024.100215","DOIUrl":"https://doi.org/10.1016/j.physo.2024.100215","url":null,"abstract":"<div><p>The models developed in this work are used to study various thermodynamic properties of nanomaterials. A better agreement between theory and experiment indicates the validity of the proposed model. Since the model is simple and easy to use, we extend the theory to understand, how the thermodynamic properties of different nanomaterials depend on size and shape. The results were compared with previous theoretical work and experimental data. We have concluded that the model predicts a better agreement with previous theoretical work and experimental studies. Current research produces thermodynamic models for the Debye frequency, melting entropy, melting enthalpy, and Einstein temperature. To the best of our knowledge, such models are not yet available in the literature that works well.</p></div>","PeriodicalId":36067,"journal":{"name":"Physics Open","volume":"19 ","pages":"Article 100215"},"PeriodicalIF":0.0,"publicationDate":"2024-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666032624000139/pdfft?md5=b5fd0063d58cb079a3eacaaca82a8dc7&pid=1-s2.0-S2666032624000139-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140547253","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Computation of hydromagnetic tangent hyperbolic non-Newtonian flow from a rotating non-isothermal cone to a non-Darcy porous medium with thermal radiative flux","authors":"S. Abdul Gaffar ,&nbsp;O. Anwar Bég ,&nbsp;S. Kuharat ,&nbsp;T.A. Bég","doi":"10.1016/j.physo.2024.100216","DOIUrl":"https://doi.org/10.1016/j.physo.2024.100216","url":null,"abstract":"<div><p>A theoretical and numerical study is conducted on nonlinear, steady-state thermal convection boundary layer flow of a magnetized incompressible Tangent Hyperbolic non-Newtonian fluid from a rotating cone to a non-Darcy porous medium. Power-law variation in temperature on the cone surface is considered and thermal radiation heat transfer is also present. The Brinkman-Darcy-Forchheimer model is deployed for the porous medium. The study is motivated by rotational (spin) coating with new emerging magnetic rheological polymers, a process which often utilizes filtration media and high temperatures. The transformed non-dimensional conservation equations are solved numerically subject to physically appropriate boundary conditions using a second-order accurate implicit finite-difference Keller Box technique. The numerical code is validated with previous studies. Extensive visualization of axial, tangential velocity components and temperature distributions with variation in key parameters including Rosseland radiative number, Darcy number, Forchheimer number (non-Darcy inertial parameter), magnetic interaction parameter, tangent-hyperbolic non-Newtonian power-law index and Weissenberg (non-Newtonian) number is included. Additionally, axial and tangential (circumferential) skin friction and Nusselt number values are tabulated for variation in key control parameters. With increasing Weissenberg number, axial velocity is depleted near the cone surface, tangential velocity is suppressed throughout the boundary layer regime and temperature is strongly enhanced. Axial flow is strongly decelerated further from the cone surface with increasing tangent-hyperbolic power-law index and there is also a significant depletion in tangential (swirl) velocity. Temperature is however boosted throughout the boundary layer transverse to the cone surface with a rise in tangent-hyperbolic power-law index. Both tangential and axial velocity are suppressed with increment in magnetic interaction parameter whereas temperature and thermal boundary layer thickness are enhanced. With larger Darcy number (i.e. greater permeability), axial velocity is strongly increased near the cone surface with no tangible modification further from the cone; However tangential velocity is consistently elevated throughout the boundary layer with greater Darcy number whereas temperature is depleted. An increase in Forchheimer number substantially damps both axial and tangential velocity whereas it elevates temperature. Increasing radiative flux strongly energizes the magnetic polymer and elevates temperature but suppresses the axial and tangential velocities. With elevation in non-isothermal wall exponent, axial skin friction is suppressed whereas Nusselt number are elevated at the cone vertex. Further along the cone surface a similar response is observed but there is also a reduction in magnitudes of tangential skin friction.</p></div>","PeriodicalId":36067,"journal":{"name":"Physics Open","volume":"19 ","pages":"Article 100216"},"PeriodicalIF":0.0,"publicationDate":"2024-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666032624000140/pdfft?md5=eed9564483fec5f5fec14b52bbf0bff3&pid=1-s2.0-S2666032624000140-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140547252","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study of MOX-fueled VVER-1000 pin cell using ν-TRAC with ENDF/B-VIII.0 library","authors":"Anmol Singh ,&nbsp;Usha Pal ,&nbsp;R. Karthikeyan ,&nbsp;V. Harikrishnan","doi":"10.1016/j.physo.2024.100212","DOIUrl":"https://doi.org/10.1016/j.physo.2024.100212","url":null,"abstract":"<div><p>This paper compares the ENDF/B-VIII.0 library for the MOX-fueled VVER-1000 pin cell benchmark with ENDF/B-VII.0 library using the <span><math><mi>ν</mi></math></span>-TRAC code and demonstrates the modeling capability of the code. <span><math><mi>ν</mi></math></span>-TRAC is a MOC-based code for simulating neutron transport in fuel assembly lattices, with the ability to model cell heterogeneities. The material cross-section significantly impacts neutron transport calculations; therefore, a 172 multigroup cross-section library has been generated using the most recent version of ENDF/B-VIII.0 and the open-source NJOY-2016 code. This nuclear data file includes modifications to the cross-section of major actinides and other light nuclides. Five MOX fuel variants differing in fuel isotopic composition and five states differing in fuel temperature, the moderator, and poison in the moderator are investigated using the most recent library. The impact of new release on the infinite multiplication factor and reactivity change due to the different operating states is studied. Results of <span><math><mi>ν</mi></math></span>-TRAC code using multigroup data libraries based on ENDF/B-VIII.0 and ENDF/B-VII.0 are compared with corresponding results from SCALE/SAS2H, HELIOS, and MCU.</p></div>","PeriodicalId":36067,"journal":{"name":"Physics Open","volume":"19 ","pages":"Article 100212"},"PeriodicalIF":0.0,"publicationDate":"2024-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666032624000103/pdfft?md5=ccd0d1d368e35955cdb7da9482ca0d5f&pid=1-s2.0-S2666032624000103-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140540006","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A review on practical challenges of aerial quantum communication","authors":"Umang Dubey ,&nbsp;Prathamesh Bhole ,&nbsp;Arindam Dutta ,&nbsp;Dibya Prakash Behera ,&nbsp;Vethonulu Losu ,&nbsp;Guru Satya Dattatreya Pandeeti ,&nbsp;Abhir Raj Metkar ,&nbsp;Anindita Banerjee ,&nbsp;Anirban Pathak","doi":"10.1016/j.physo.2024.100210","DOIUrl":"https://doi.org/10.1016/j.physo.2024.100210","url":null,"abstract":"<div><p>The increasing demand for the realization of global-scale quantum communication services necessitates critical investigation for a practical quantum secure communication network that relies on full-time all-location coverage. In this direction, the non-terrestrial quantum key distribution is expected to play an important role in providing agility, maneuverability, relay link, on-demand network, and last-mile coverage. In this work, we have summarized the research and development that has happened until now in the domain of quantum communication using non-terrestrial platforms with a specific focus on the associated challenges and the relevant models. Further, to extend the analysis beyond the existing know-how, a hybrid model involving the features of Vasylyev et al.’s model and Liorni et al.’s model is introduced here. The hybrid model entails us adapting a spherical beam to an elliptic beam approximation and effectively capturing the characteristics of transmittance in densely humid weather conditions and at low altitudes.</p></div>","PeriodicalId":36067,"journal":{"name":"Physics Open","volume":"19 ","pages":"Article 100210"},"PeriodicalIF":0.0,"publicationDate":"2024-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666032624000085/pdfft?md5=2b873294f9cd3e5f2fa425293f85b082&pid=1-s2.0-S2666032624000085-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140535395","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Orthorhombic structure and optoelectronic properties of 3d transition metal diantimonides TMSb2 (TM2+ = V, Cr, Fe)","authors":"M. Musa Saad H.-E. ,&nbsp;A. Almeshal ,&nbsp;B.O. Alsobhi","doi":"10.1016/j.physo.2024.100213","DOIUrl":"https://doi.org/10.1016/j.physo.2024.100213","url":null,"abstract":"<div><p>Inorganic transition-metal materials have attracted widespread attention in the field of opto-spintronics technology due to their unique optical and electronic structures. Tuning the physical properties of diantimonide materials by introducing 3d transition-metal (TM) elements is an effective means to obtain functional compounds to be applicable in the field of optoelectronics devices. In this regard, based on ab-initio calculations, we have investigated the structural, electronic and optical properties of diantimonides TMSb₂ (TM = V, Cr, Fe) according to the density functional theory (DFT) executed in Wien2k package. The Perdew-Burke-Ernzerhof (PBE) functional under generalized gradient approximation (GGA) and (GGA + U) are adopted to carry out the exchange correlation calculations. Our DFT results demonstrate that TMSb₂ crystalize in marcasite structure with orthorhombic symmetry (S.G.: Pnnm, #58, Z = 2). Utilizing the PBE-GGA and PBE-GGA + U methods, we calculated the band structure, as well as the total density of states and partial density of states, which confirm that the TMSb₂ materials exhibit ferromagnetic metallic behavior. In addition, the optical properties are investigated as a function of photon energy and we found that TMSb₂ show favourable absorption, conductivity, refractivity, and reflectivity. The high optoelectronic responses at the low energies make TMSb₂ promising materials for optoelectronics applications.</p></div>","PeriodicalId":36067,"journal":{"name":"Physics Open","volume":"19 ","pages":"Article 100213"},"PeriodicalIF":0.0,"publicationDate":"2024-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666032624000115/pdfft?md5=c771b4fd056770606b96832c16e1c56b&pid=1-s2.0-S2666032624000115-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140547254","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spatial-temporal dynamics of stimulated Raman scattering: Effects of populations and two-photon detuning","authors":"C.H. Raymond Ooi,&nbsp;Yuzhao Huang,&nbsp;Jong Wey Lee","doi":"10.1016/j.physo.2024.100211","DOIUrl":"https://doi.org/10.1016/j.physo.2024.100211","url":null,"abstract":"<div><p>A quantum theory of stimulated Raman scattering is established that takes into account the time-dependence of pump laser pulse, two-photon detuning and atomic populations, allowing the general transient and spatial propagation study of Raman memory. Heisenberg–Langevin and Maxwell equations for the collective atomic operators are solved analytically under adiabatic condition, where the electric field envelopes and the collective atomic operators vary slowly. The analytical solution of Stokes/anti-Stokes signal electric field operator is obtained. The spatial–temporal intensity of quantum signal field is studied numerically and analytically for different two-photon detunings and initial populations.</p></div>","PeriodicalId":36067,"journal":{"name":"Physics Open","volume":"19 ","pages":"Article 100211"},"PeriodicalIF":0.0,"publicationDate":"2024-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666032624000097/pdfft?md5=b174baab00c868f61eb3abf8f4e58a9c&pid=1-s2.0-S2666032624000097-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140535394","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Physical studies of chitosan/PEG loaded Fe2O3 nanoparticles microbeads as a based biodegradable material for radiation shielding","authors":"M. Elotaiby,&nbsp;Asmaa M. Elzayat,&nbsp;W.M. Awad,&nbsp;M. Abdelaziz,&nbsp;E.M. Abdelrazek","doi":"10.1016/j.physo.2024.100209","DOIUrl":"https://doi.org/10.1016/j.physo.2024.100209","url":null,"abstract":"<div><p>This work reports two different strategies for the formation of hybrid microbeads using chitosan and polyethylene glycol (PEG) as based biodegradable materials for radiation shielding. An organic–inorganic hydrogel was prepared by ionotropic gelation. During the in-situ loading, incorporating magnetic nanoparticles Fe₂O₃ into the polymer matrix, magnetic nanostructures, were entrapped in the polymer matrix during the physical cross-linking of the polymer with the physical cross-linker (sodium triphosphate). However, in case of post-loading mechanism the loaded nanoparticles favor the precipitation on the surface of the formed beads. We use different characterization techniques for our systems such as scanning electron microscopy (SEM), x-ray, infrared spectroscopy (XRD), and X-ray radiation shielding application. The results demonstrate that by incorporating nanostructured magnetic particles into the polymer matrix, the surface morphology based on the two processes allow the magnetic nanoparticles to be embedded or form an outer shell and precipitated on the surface of polymer microbeads. The values of μ for the hydrogels loaded with Fe₂O₃ by in-situ process have the larger values of the linear coefficient however, in case of post-loading process the values dramatically decrease in compare with the in-situ ones at the same tube voltage. The presented work recommended as a good mentor for radiation shielding.</p></div>","PeriodicalId":36067,"journal":{"name":"Physics Open","volume":"19 ","pages":"Article 100209"},"PeriodicalIF":0.0,"publicationDate":"2024-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666032624000073/pdfft?md5=e3ee2fd975af74dbd758415f252640e1&pid=1-s2.0-S2666032624000073-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140320530","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Scalable surface ion trap design for magnetic quantum sensing and gradiometry","authors":"Qirat Iqbal,&nbsp;Altaf Hussain Nizamani","doi":"10.1016/j.physo.2024.100208","DOIUrl":"https://doi.org/10.1016/j.physo.2024.100208","url":null,"abstract":"<div><p>Magnetic quantum sensors based on trapped ions utilize properties of quantum mechanics which have optimized precision and beat current limits in sensor technology. Trapped ions are highly sensitive in a large span of signal ranging from DC or static B-field to the radiofrequency range in 100s of MHz and can attain the sensitivity in the range of <span><math><mrow><mtext>pT</mtext><mo>/</mo><msqrt><mtext>Hz</mtext></msqrt></mrow></math></span> to sub-<span><math><mrow><mtext>pT</mtext><mo>/</mo><msqrt><mtext>Hz</mtext></msqrt></mrow></math></span>. They are tuneable to frequencies of interest and can be used as a lock-in frequency detector. This modelling and simulation based study presents an innovative design of Surface Paul Traps, enabling the use of trapped ions as ultra-sensitive sensors for magnetic field detection and precise measurement of magnetic field gradients at a sub-millimeter spatial resolution. The novel design features multiple trapping regions, allowing for the mapping of magnetic fields across various ion-trapping zones. The study demonstrates groundbreaking advancements in ion manipulation and confinement through innovative chip architecture.</p></div>","PeriodicalId":36067,"journal":{"name":"Physics Open","volume":"19 ","pages":"Article 100208"},"PeriodicalIF":0.0,"publicationDate":"2024-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666032624000061/pdfft?md5=68bb7da35d20599495d3d99f38ac4547&pid=1-s2.0-S2666032624000061-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139986765","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparison between variations in solar UV radiation and sunspot parameters with Mg II daily index as a proxy","authors":"(G) Chandrika ,&nbsp;Belur Ravindra ,&nbsp;Vijay Kumar Doddamani","doi":"10.1016/j.physo.2024.100204","DOIUrl":"10.1016/j.physo.2024.100204","url":null,"abstract":"<div><p>Solar UV radiation influence the Earth's climate and upper atmosphere. The UV emission from the Sun modulates with the sunspot cycle with an 11-year periodicity. The variations in UV, EUV, and X-rays emission are significant during the solar cycle evolution compared to the visible part of the spectrum. The h &amp; k lines of the Mg II spectra emitted from the chromosphere represent the solar UV variability. The sunspot's magnetic fields and dynamics are responsible for the UV and EUV emissions from the solar chromosphere and corona. This paper compares the Mg II core-to-wing ratio of the h &amp; k lines observed at 278 nm wavelength (obtained from Solar Backscattered Ultraviolet Spectrograph (SBUV) instrument onboard the NOAA satellite) with the sunspot area parameter obtained from Royal Greenwich Observatory. When the sunspot group area is small, there is a linear relationship between the sunspot group area and the Mg II index. But a non-linear relationship between the two is observed for the large sunspot group area. There is no phase delay between the appearance of sunspot groups on the solar photosphere and the emission from the Mg II doublet. Apart from 11-year periodicity, we observed common 4.7, 3.2, and 2.2-year periodicity in both the data sets, suggesting the Mg II index is related to the sunspot parameters.</p></div>","PeriodicalId":36067,"journal":{"name":"Physics Open","volume":"19 ","pages":"Article 100204"},"PeriodicalIF":0.0,"publicationDate":"2024-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666032624000024/pdfft?md5=3bb479717c16f0632c4bc79d76bd67c6&pid=1-s2.0-S2666032624000024-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139885103","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}